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PubMedDate not supplied

[Colloid cysts of the pituitary gland].

Colloid cysts of the pituitary gland are very rare pathological lesions occurring in sellar region. Their pathogenesis is not clear. They are located between the anterior and posterior lobe of the pituitary. Colloid cysts of the pituitary gland are space occupying lesions and induce hypopituitarism, diabetes insipidus, visual disturbances, etc. They cause pituitary apoplexy too. Magnetic resonance imaging is the preferred neurodiagnostic method in evaluating these lesions. 503 transsphenoidal procedures were performed from January 1996 to February 2001. Hypothalamo-hypophyseal dysfunction was caused by colloid cyst in seven cases. The most frequent presenting symptoms were headaches, oligomenorrhea and loss of libido. Diabetes insipidus was found in two cases before surgery. Colloid cyst induced pituitary apoplexy in one patient. Two patients presented visual disturbances. All our patients were operated on. We performed six transsphenoidal procedures and one transcranial operation. Postoperatively, the endocrine function of the pituitary gland was evaluated. We concluded that transsphenoidal operation is a safe method for treating colloid cyst located in the sellar region.

Adult↗
PubMedDate not supplied

[Colloid cyst of the third ventricle: case description and survey of the literature].

INTRODUCTION: Colloid cysts are intracranial lesions with an estimated incidence of three individuals per million people per year. They are benign tumours in the anterosuperior portion of the third ventricle. The normal flow of cerebrospinal fluid may be interrupted by a large cyst that obstructs the foramen of Monro. The associated signs and symptoms cover a wide range of features, from non specific headaches to intracranial hypertension data; some colloid cysts occur at the acute onset of hydrocephalus and can lead to a sudden death. CASE REPORT: We present the case of a patient with a colloid cyst in the anterior roof of the third ventricle, with the presence of a dysfunctional ventriculo peritoneal bypass valve, which had been introduced three years earlier. Both events contributed to the development of a hydrocephalus with clinical manifestations of intracranial hypertension. The images obtained by magnetic resonance (MR) revealed the presence of a hyperintense mass of variable density in the roof of the third ventricle and in its rostral face; the image was hyperintense in T1 and isointense in T2. The patient was submitted to an endoscopic cisternoventriculostomy to allow the surgical drainage of the colloid cyst, and management was continued in the outpatients department of the Neurosurgery Service. CONCLUSIONS: In this paper we discuss the main characteristics of the colloid cyst, some considerations on its presentation in MRI are presented and a brief survey of the literature is also conducted.

Adult↗
PubMed2002

Preliminary studies with 188rhenium-tin colloid for radiation synovectomy: preparation, size determination, in-vivo distribution, effect and dosimetry studies.

BACKGROUND: Generator-produced beta-emitting radionuclides such as (188)Re are gaining in importance for radiosynoviorthesis because of their availability on a regular basis. MATERIAL AND METHODS: We prepared a (188)Re-tin colloid in a reaction carried out either at 100 degrees C or at room temperature (RT). The size of the colloid particles was measured with a laser lightscattering method, and their biodistribution, dosimetric aspects and therapeutic effects were studied in an antigen-induced arthritis (AIA) model in rabbits. (188)Re-tin colloid solution was injected intra-articularly into the knee joints of rabbits with AIA and imaging studies were performed. Blood samples were collected post injection for estimation of the blood residence time. We also injected 2 intact rabbits in the same manner with (188)Re perrhenate solution in order to observe its effects and distribution in the body. All the treated rabbit knees were subjected to histopathology. RESULTS: The colloid particle size distribution was different after preparation at the different reaction temperatures, with a more suitable mean of 4.53 micro m in the RT preparation. The dose delivered to the synovial surface was between 3.51 and 4.21 Gy and that to the bone surface was between 0.70 and 0.84 Gy. Histopathologic examination revealed the development of fibrous connective tissue in the AIA knees 4 weeks after treatment, but not in the control group. CONCLUSIONS: The (188)Re-tin colloid preparation used in this study was suitable for radiation synovectomy application. It requires modifications in the preparation protocol so as to increase the labeling efficiency in correlation with an appropriate particle size.

Journal Article↗
PubMed1991

Quantitative evaluation of four 99Tcm colloids for bone marrow scintigraphy using single photon emission computed tomography.

Colloids used for bone marrow scintigraphy are also taken up in the liver and spleen. The liver activity in particular hampers interpretation of the study. In this study, four small-sized commercial colloids labelled with 99Tcm were compared for bone marrow uptake relative to the liver, spleen and background activity. Three human albumin colloids (Microlite, E.I. du Pont de Nemours & Co; Solco Nanocoll, Solco Nuclear; TCK-9, International CIS) and one antimony sulphide colloid (TechneScan Sb2S3, Mallinckrodt Diagnostics) were compared. The study was performed in patients routinely referred for liver/spleen scintigraphy who had a normal result. Each examination was carried out using single photon emission computed tomography. After correction for attenuation and scattering of photons, the activity of the bone marrow of the lumbar spine was related to the liver, spleen and background activity. The bone marrow/liver activity quotient of Solco Nanocoll and TCK-9 was almost twice the value for Microlite and TechneScan Sb2S3. The bone marrow/spleen quotient was almost four times higher and the bone marrow/background quotient almost twice as high for Solco Nanocoll as for the other three colloids, between which there were no significant differences.

Antimony↗
PubMed1987

Detection of the low density lipoprotein (LDL) receptor on nitrocellulose paper with colloidal gold-LDL conjugates.

Gold-low density lipoprotein (LDL) conjugates were used to detect the LDL receptor on nitrocellulose paper. Solubilized rat liver membrane proteins were subjected to electrophoresis and electroblotted onto nitrocellulose paper. The receptor was then detected as a red band (within 10 min) by overlaying with the LDL conjugates. The coloration was prevented by unlabeled LDL, EDTA, and suramin but not by unlabeled HDL3. In the dot blot assay, detection with the colloidal gold-LDL conjugates was as sensitive as both the autoradiographic method with 125I-labeled LDL and the biotinylated LDL method; the estimated limit of detection by scanning densitometry was 1.6 femtomoles of receptor protein. When the coloration obtained with the colloidal gold-LDL conjugates was intensified by photochemical silver staining, down to 200 attomoles of the LDL receptor could be detected. In this assay, the EDTA-sensitive binding of colloidal gold-LDL to solubilized hepatic membrane proteins was 12 times higher for rats treated with 17 alpha-EE than for normal rats. The use of colloidal gold-LDL conjugates is therefore a very easy, safe, inexpensive, fast and sensitive method for the detection of the LDL receptor on nitrocellulose paper. Furthermore, with silver staining and scanning densitometry, the colloidal gold-LDL conjugates could be used in a dot blot assay to quantify tissue and cell LDL receptors down to attomolar levels.

Animals↗
PubMed1982

Colloid bodies in dermatoses other than lichen planus.

In a previous study on lichen planus the morphology and significance of the colloid bodies were discussed (13). In the present study a description is given of 30 dermatoses with colloid bodies, observed among unselected patients. The colloid bodies develop as a result of damage to the epithelium caused by circulatory disorders with subsequent hypo- or anoxia. Lichenoid cell infiltration into the connective tissue--nearly always present--aggravates the process. Dyskeratosis, pyknosis and fibrinoid necrosis of the damaged cells occur and the nuclei disintegrate. The resultant colloid bodies may coalesce or scatter or be expelled from the epithelium according to the principles of apoptosis (6, 7). Besides circulatory disorders, purely local damage and pathological processes involving the tissues should be regarded as important factors. Although the colloid bodies are characteristic for various skin diseases, they do not have an absolutely clear diagnostic significance. In doubtful cases their presence may nevertheless be considered a valuable contribution and supplement to the diagnosis.

Amyloid↗
PubMed1980

[Influence of surgery and hemodilution on the colloid osmotic pressure].

Colloid osmotic pressure was measured pre- and postoperatively in 75 patients. It could be demonstrated that the level of the colloid osmotic pressure inaccurately corresponded to the serum protein concentration. This fact can be neglected in those patients that are infused for short-term periods. However, many patients receive large amounts of colloids during long-term parenteral nutrition and in those cases an abnormal increase of plasma volume has to be expected. This might be harmful to the cardiopulmonary function and can be avoided by infusing colloids according to the level of the colloid osmotic pressure.

Adult↗
PubMed1978

Colloid osmotic and pulmonary wedge pressures in acute respiratory failure following hemorrhage.

Acute respiratory failure evolved in five patients following hypovolemic shock related to trauma or surgical operation, or both. A reduction in colloid osmotic pressure, increases in pulmonary artery wedge pressure and reductions in colloid osmotic pressure-pulmonary artery wedge pressure gradient to levels which are likely to account for pulmonary edema were observed. Accordingly, reduction in the colloid hydrostatic pressure gradient may, in part, explain the development of acute respiratory failure after acute blood loss. In one instance, however, the absence of such reduction in the colloid osmotic pressure-pulmonary artery wedge pressure gradient together with increases in pulmonary vascular resistance showed that colloid osmotic pressure and pulmonary artery wedge pressure are not exclusively operative in the pathogenesis of the clinical syndrome of acute respiratory failure.

Acute Disease↗
PubMed1982

Dosimetry in lymphoscintigraphy of Tc-99m antimony sulfide colloid.

A quantitative kinetic technique using a scintillation camera has been developed for investigating lymph drainage and the uptake in the lymph nodes of 99mTcSb2S3 colloid injected subcutaneously. Twenty-two patients with primary malignant melanoma were examined. Lymph-node dissection was performed and 185 lymph nodes were individually measured for radioactivity. The kinetics of colloid uptake in individual nodes can be expressed by a simple two-compartment model. The outflow of colloid from the injection site was found to be monoexponential, and the tissue volume containing the injected colloid at the injection site increased asymptotically with time. A model has been developed for calculating absorbed doses at the injection site and in organs with colloid uptake. The following absorbed doses were estimated (muGy/MBq): whole body 0.7-4.5, gonads 0-22, liver 1.0-3.9, lymph nodes up to 1000 and injection site about 10,000. Possible biological effects in the skin and effective dose equivalents have been estimated when using other lymphoscintigraphic agents.

Antimony↗
PubMed1982

Studies on quantitative morphology. VI. Morphometry of colloid and epithelium in the thyroid gland.

The colloid and epithelium percentages in the thyroid gland are characterized by a noticeable variability and a zonal heterogeneity; in the border region an enriching of the colloid component is observed and in the central part a higher epithelium concentration. Studies with different net point distances and measuring areas led to the following conclusions: provided that a sufficient number of points are attached, a distance of 250 micrometers may be used for common tests; the prolongation of the measuring time for lower distances than 100 micrometers is often not accompanied by an essentially better accuracy. Measuring areas should not be too small, even between fields of 20 mm2 differences of the few per cents may be observed in the same slide. The polynomial regression curve for the comparison of epithelium and colloid data seems to be influenced by the interstitium values: up to about 30% colloid an increase of the epithelium values is seen, since a further growing of the colloid percentages is connected with a decline of the epithelium percentages.

Animals↗
PubMed1997

Rhenium-188 labeled hydroxyapatite and rhenium-188 sulfur colloid. In vitro comparison of two agents for radiation synovectomy.

AIM: One therapeutic approach to rheumatoid arthritis and other inflammatory arthropathies besides surgical removal of inflamed synovium is radiation synovectomy using beta-emitting radionuclides to destroy the affected synovial tissue. Up to now the major problem associated with the use of labeled particles or colloids has been considerable leakage of radionuclides from the injected joint coupled with high radiation doses to liver and other non target organs. In this study we compared 188Re labeled hydroxyapatite particles and 188Re rhenium sulfur colloid for their potential use in radiation synovectomy. METHODS: To this end we varied the labeling conditions (concentrations, pH-value, heating procedural and analyzed the labeling yield, radiochemical purity, and in vitro stability of the resulting radiopharmaceutical. RESULTS: After optimizing labeling conditions we achieved a labeling yield of more than 80% for 188Re hydroxyapatite and more than 90% for the rhenium sulfur colloid. Both of the radiopharmaceuticals can be prepared under aseptic conditions using an autoclave for heating without loss of activity. In vitro stability studies using various challenge solutions (water, normal saline, diluted synovial fluid) showed that 188Re labeled hydroxyapatite particles lost about 80% of their activity within 5 d in synovial fluid. Rhenium sulfur colloid on the other hand proved to be very stable with a remaining activity of more than 93% after 5 d in diluted synovial fluid. CONCLUSION: These in vitro results suggest that 188Re labeled rhenium sulfur colloid expects to be more suitable for therapeutic use in radiation synovectomy than the labeled hydroxyapatite particles.

Arthritis, Rheumatoid↗
PubMed1976

[Colloid cysts of the third ventricle --report of one operated and one autopsied case (author's transl)].

Colloid cysts of the third ventricle are considered as a relatively rate benign tumor, consituting approximately 0.5% of the whole brain tumors, but the surgical cases have rarely been reported in Japan. In this paper, two cases of colloid cyst are reported and the pathogenesis, the importance of the clinical diagnosis and dramatic results after complete extirpation was emphasized. In Case 1, a 29 year-old right handed male, who showed definite symptoms of increased intracranial pressure without lateralizing signs, was diagnosed as colloid cyst of the third ventricle, and operated on with dissecting microscope on April 20, 1973. The colloid cyst was totally removed and postoperatively V-A shunt was performed for adhesive arachnoiditis. Patient did well after surgery and has returned to the previous work. In Case 2, a 41 year-old male, who suffered from sudden onset of severe headache and bouts of frequent vomiting, was admitted to Tokyo Wome's Medical College Hospital on October 11, 1974. Right cerebral angiography revealed findings of increased intracranial pressure and third ventricle tumor was suspected. On October 13, progressively disturbed consciousness occurred. Immediate ventricular tap and continuous ventricular drainage could not regain consciousness and patient expired on October 30. In necropsy, colloid cyst to the third ventricle was found. As far as these are concerned, these cysts might be reasonably said as ventricular epithelial origin in view of the operative and histological findings. Some emphasis was also made in terms of dissecting microscope in removing this tumor, completely preserving the ventricular walls as well as the terminal veins under magnification.

Adult↗
PubMed1986

Technetium-sulfur colloid.

The chemistry of the technetium-sulfur colloid produced by the reaction of sodium thiosulfate with acid was investigated. A commercial kit was duplicated, and analyses of elemental sulfur, bisulfite and residual thiosulfate were carried out. The colloidal dispersions were filtered through Nuclepore graded membranes, and the percentages of sulfur and of 99mTc in the various filtrates were determined. In all cases--with varying acid, thiosulfate and time of incubation--there was a rough agreement between the two percentages for particles 0.4 micron in diameter or more. However, for small particles (less than 0.1 micron) there was virtually no sulfur, but there was an appreciable percentage of technetium. It was concluded that the technetium sulfide nuclei formed first, and that the supersaturated sulfur deposited in part on them and in part on its own nuclei. It was found that raising the pH of the preparation to weakly alkaline values and reheating the solution dissolved most of the deposited sulfur by the reaction with sulfite to form thiosulfate, leaving much smaller, virtually sulfur-free technetium sulfide particles. Such a preparation was found to be as efficient as the technetium-antimony sulfide colloid for lymphograms in dogs. Potassium trithionate, K2S3O6, used in place of sodium thiosulfate, produced small Tc-S colloid particles with less sulfur than the conventional thiosulfate-acid system.

Animals↗
PubMed2000

Lymphoscintigraphy using larger colloid particles may enhance visualization of the sentinel node in breast cancer: a case report.

Lymphoscintigraphy along with a gamma-detecting probe has been applied successfully to breast cancer patients to localize the sentinel node during surgery, with a 5% false-negative rate. The authors report a case of stage II breast cancer. The sentinel node was not visualized on the initial lymphoscintigraphy with peritumoral injection of 37 MBq (1 mCi) 10 ml Tc-99m colloidal rhenium sulfide (Tc-99m ReS colloid; average particle size, 100 nm). However, the sentinel node was visualized in the left lateral view of the second lymphoscintigraphy with peritumoral injection of 37 MBq (1 mCi) 10 ml Tc-99m ReS colloid (average particle size, 500 nm). Lymphoscintigraphy using the larger colloid particles may enhance visualization of a sentinel node in breast cancer.

Adult↗
PubMed1986

Problems in the production and use of 5 nm avidin-gold colloids.

Over the past 5 years we have encountered several problems in the production and use of 5 nm avidin-gold colloids for markers in electron microscopy. These problems include flocculation of colloids during reduction of chloroauric acid, insoluble gold pellets following ultracentrifugation, and non-specific binding of avidin-gold colloids to biological membranes. We are able to avoid these problems by: avoiding the use of crystalline chloroauric acid; succinoylating egg white avidin prior to adsorption on the gold sols; resuspending the pellets following ultracentrifugation in 5 mM phosphate buffer, pH 7.5; and using the avidin-gold colloids within 4 weeks of production.

Animals↗
PubMed1995

A paradigm for consensus. The University Hospital Consortium guidelines for the use of albumin, nonprotein colloid, and crystalloid solutions.

OBJECTIVE: To develop contemporary, comprehensive guidelines for the appropriate and efficient use of albumin, nonprotein colloid, and crystalloid solutions. DESIGN: A systematic, literature-based, consensus exercise employing a modified Delphi method. PARTICIPANTS: Thirty-one medical and allied health professionals from 26 University Hospital Consortium (Oak Brook, Ill) member institutions were initially chosen to participate. Participants were selected on the basis of their recognized research in the use of albumin, nonprotein colloid, and crystalloid solutions, and/or experience in the review of appropriateness of such use. A total of 24 participants completed the exercise. MAIN OUTCOME MEASURES: Group responses were statistically analyzed in an iterative consensus development process. Five separate questionnaire rounds were designed to establish criteria for the appropriate use of albumin, nonprotein colloid, and crystalloid solutions. RESULTS: Consensus guidelines were developed outlining the appropriate use of these products for 12 clinical indications, including hemorrhagic shock, nonhemorrhagic (maldistributive) shock, hepatic resection, thermal injury, cerebral ischemia, nutritional intervention, cardiac surgery, hyperbilirubinemia of the newborn, cirrhosis and paracentesis, nephrotic syndrome, organ transplantation, and plasmapheresis. CONCLUSIONS: The Delphi method, a systematic, literature-based consensus process, was shown to be useful in the development of complex clinical practice guidelines for the use of albumin, nonprotein colloid, and crystalloid solutions. It is anticipated that the guidelines will assist health care providers to develop local institutional policies and procedures for the appropriate and efficient use of albumin and albumin alternatives. Institutions reviewing and updating existing local guidelines may use the University Hospital Consortium guidelines as a model for comparison.

Academic Medical Centers↗
PubMed1995

Distribution of colloidal gold tracer within rat parasternal lymph nodes after intrapleural injection.

BACKGROUND: Tracer studies are an important tool to obtain information about the processes involved in the immunological response. Colloidal gold is widely used as a tracer, but its small size of label can cause some difficulty during low-resolution analysis. To overcome this difficulty, we developed a new method to follow the route of tracer movement within lymph nodes. METHODS: We applied conventional X-ray analysis, X-ray fluorescence analysis (XFA) subtractional microscopy using synchrotron radiation (SR) beams, light microscopy, and ultrastructural analysis to study the distribution and quantity of colloidal gold coupled with albumin within rat parasternal lymph node 2, 4, 6, 8, and 10 h after intrapleural injection of the tracer. RESULTS: At all the time points XFA-SR revealed that tracer formed a circle with a maximum concentration in the node periphery. XFA-SR measured colloidal gold concentration in the nodes reached its maximum (0.5-0.75 weight %) in 6-8 h. Subtractional microscopy revealed superficially located groups of cells filled with colloidal gold tracer. Light microscopy and ultrastructural analysis confirmed that the tracer was concentrated in the reticular cells, situated in the sinuses of the node. Sinusoidal reticular cells concentrated tracer at much higher rates than sinusoidal macrophages. Four hours after injection, gold appeared in the lysosomes of the follicular reticular cells. At the same time point, evidence of antigen presentation was obtained. Antigen presentation proved to be an extremely rara event since only one ultrastructural incident was found in 150 analysed grids. CONCLUSIONS: SR is a valuable tool for the analysis of gold tracer passage within the living organism.

Animals↗