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PubMed2005

A case of familial third ventricular colloid cyst.

Colloid cyst of the third ventricle is a rare benign intracranial lesion, and familial cases are rarer still. They may be asymptomatic or present with symptoms of raised intracranial pressure, including sudden death. Surgical excision is curative. We report a 24 year old pregnant woman with familial colloid cyst, who presented with headaches and suffered a cardiorespiratory arrest. Early computed tomography scan of the brain is advised in patients with a family history of third ventricular colloid cyst presenting to the accident and emergency department with headache.

Adult↗
PubMed1988

Treatment of ulcerative reflux oesophagitis with colloidal bismuth subcitrate in combination with cimetidine.

Twenty patients took part in a controlled double blind study comparing the efficacy of colloidal bismuth and cimetidine (800 mg at night) with cimetidine alone in the treatment of ulcerative reflux oesophagitis. Colloidal bismuth 120 mg was administered through an intraoesophageal tube four times a day. Cimetidine with colloidal bismuth gives significantly (p less than 0.001) better results than cimetidine alone. Of 10 patients treated with cimetidine and bismuth, seven had no endoscopic signs of oesophagitis after three weeks and three had grade I oesophagitis. Of 10 patients treated with cimetidine alone, one had grade I oesophagitis and three grade II oesophagitis after three weeks. The remaining six still had grade III oesophagitis. This study also shows that in nine of 10 patients reflux oesophagitis was accompanied by infection with campylobacter like organisms (CLO). After treatment the bacteria disappeared promptly in five patients receiving combination therapy and in two of four treated with cimetidine alone. The possible role of CLO in reflux oesophagitis is uncertain.

Aged↗
PubMed1990

Effect of repeated colloidal bismuth subcitrate treatment on the response of the rat gastric mucosa to the presence of luminal ethanol.

The purpose of this study was to determine the effects of repeated colloidal bismuth subcitrate administration on the cellular populations of the fundic region of the rat stomach and to investigate the effect of such treatment, after initial ethanol damage, on the gastric response to a second challenge by ethanol. The administration of 240 mg of colloidal bismuth subcitrate per kilogram body weight, at 12 hour intervals, for 14 days, resulted in an increase in the density of the mucosal epithelial cells, but a decreased rate of epithelial cell division in the neck region. Comparison with placebo treated animals showed that the repeated administration of colloidal bismuth subcitrate after an initial ethanol challenge, decreased the degree of damage induced by a second ethanol challenge, enhanced the rate of tissue repair and prevented the establishment of persistent erosions.

Animals↗
PubMed1993

Short and long term outcome of Helicobacter pylori positive resistant duodenal ulcers treated with colloidal bismuth subcitrate plus antibiotics or sucralfate alone.

Thirty two patients with Helicobacter pylori positive duodenal ulcers resistant to treatment were randomly assigned to 4 weeks' treatment with sucralphate 4 g/day or colloidal bismuth subcitrate 480 mg/day plus amoxycillin from days 1 to 7 and tinidazole from days 8 to 14. After 4 weeks, patients with unhealed ulcers were crossed over to the other form of treatment for a further 4 week period. Patients with healed ulcers were followed up for 1 year without maintenance therapy with clinical and endoscopic investigations 3, 6, and 12 months after healing. Complete healing rates at 4 weeks were 88% (15 of 17) in the colloidal bismuth subcitrate plus antibiotics group and 40% (six of 15) in the sucralphate group (p < 0.05). After cross over, overall healing rates were 88% (22 of 25) and 47% (eight of 17), respectively (p < 0.05). H pylori eradication occurred in 83% of patients treated with the triple therapy. Cumulative relapse rates at 12 months were 12% (two of 17) in patients in whom H pylori had been eradicated and 100% (10 of 10) in those with persistent infection after short term therapy (p < 0.05). These results show that a colloidal bismuth subcitrate plus antibiotics regimen is highly effective in the short term treatment of resistant duodenal ulcers and that H pylori eradication can change the natural tendency to early recurrence of these ulcers.

Adult↗
PubMed1977

Effect of basement membrane and colloid osmotic pressure on renal tubule cell volume.

Renal tubule cell volume is thought to be kept constant by a cation pump. When active transport is blocked, intracellular impermeant solutes cause cells to swell. Cell size is then determined by transmembrane hydrostatic and colloid osmotic forces. We studied the importance of passive transmembrane forces in determining cell size in isolated rabbit proximal straight tubules (PST). We blocked active solute transport with ouabain and evaluated subsequent changes in cell size by measuring outer diameter of nonperfused tubules. Tubules in a ouabain and 6 g/100 ml protein bath swelled only 40% above control. However, removal of the tubule basement membrane with collagenase dissipated a transmembrane hydrostatic pressure and caused more swelling. Final cell volume was determined largely by bath protein concentration. Tubules in ouabain and collagenase swelled enormously in hyponcotic protein, moderately in isoncotic protein, and could be shrunk below control in hyperoncotic protein. Intracellular colloid osmotic pressure was estimated to exceed 38 cmH20. We conclude that hydrostatic and colloid osmotic forces are major determinants of cell size in isolated PST treated with ouabain.

Animals↗
PubMed1999

Intracranial nasal dermoid sinus cyst associated with colloid cyst of the third ventricle. Case report and new concepts.

A case of a 16-year-old male with both a nasal dermoid sinus cyst (NDSC) and a third ventricle colloid cyst is presented. The NDSC was excised via a single-stage combined intracranial-extracranial approach and the third ventricle colloid cyst was resected endoscopically. The pathogenetic theories of NDSC and third ventricle colloid cyst are discussed, and an embryological explanation for the simultaneous development of the two lesions in this patient is explored. This case is best classified among congenital developmental malformations in a category we propose to call 'anterior neuropore corridor defects.'

Adolescent↗
PubMed2006

Assessment of memory and new learning ability following stereotaxy-guided transcortical resection of anterior third ventricular colloid cysts.

In a prospective study, memory and new learning ability functions were assessed pre-operatively (17 patients) and in the early post-operative period (22 patients) at 7-26 days following surgery in patients undergoing stereotactic transcortical excision of their colloid cysts. Pre-operative assessment detected impaired memory in 5 patients, 2 of whom had no memory-related complaints. Impaired new learning ability was detected pre-operatively in 7 patients. There was a statistically non-significant trend towards improvement in the dysfunction scores post-operatively in most patients. No correlation was detected between the cyst size, presence of raised intracranial pressure at presentation, hydrocephalus and the pre-operative dysfunction scores. Stereotactic transcortical resection of colloid cysts does not impair these functions in the majority of patients and might improve these functions in some. In the absence of clinical or radiological predictors of dysfunction of memory and new learning ability, pre-operative neuropsychological assessment has a role in detecting impaired memory and new learning ability in patients with anterior third ventricular colloid cysts who may not even complain of them.

Adolescent↗
PubMedDate not supplied

Metastatic minor salivary gland colloid carcinoma in the parotid region after parotidectomy for pleomorphic adenoma: a case report.

BACKGROUND: Primary colloid or mucinous carcinoma of the salivary glands is extremely rare. Only a few cases have been reported that originated in the minor salivary glands. an even more exceptional presentation is as a metastatic tumor in the parotid region subsequent to superficial parotidectomy for pleomorphic adenoma. The case presented here posed a diagnostic dilemma that could be resolved only after a thorough reevaluation of the previous cytologic and histologic material and detection of the occult primary tumor in the hypopharynx following an extensive clinical and radiologic workup. CASE: A 75-year-old female underwent fine needle aspiration of the left parotid and was diagnosed as having pleomorphic adenoma. A superficial parotidectomy removed the tumor completely, and the diagnosis was confirmed. Six months following the surgery, the patient developed an enlarged nodular mass in the ipsilateral parotid region, with fine needle aspiration showing colloid (mucinous) adenocarcinoma, which proved to be a metastatic colloid (mucinous) carcinoma on excisional biopsy. The clinical and radiologic workup in search of a primary lesion led to an occult tumor in the left hypopharyngeal mucosa. CONCLUSION: Unusual presentations of rare tumors can cause considerable diagnostic difficulties to both the clinician and cytopathologist. Awareness of these rarities is important to ensure the best patient care and to avoid unnecessary investigative and therapeutic procedures.

Adenoma, Pleomorphic↗
PubMed2000

Anaesthetic management of a parturient with a colloid cyst of the third ventricle.

A colloid cyst in the third ventricle near the foramen of Monroe can obstruct cerebrospinal fluid (CSF) flow from the lateral ventricles. Any change in the CSF pressure on either side of the cyst can lead to displacement and thus precipitate acute hydrocephalus. Management of the confinement of a patient with a colloid cyst must therefore aim to minimize changes in CSF pressure. We describe our management of a patient with a small colloid cyst who was permitted to labour with the assistance of patient-controlled epidural analgesia. The available alternatives are discussed.

Adult↗
PubMed1991

Binding and endocytosis of thrombospondin and thrombospondin fragments in endothelial cell cultures analyzed by cuprolinic blue staining, colloidal gold labeling, and silver enhancement techniques.

We investigated the distribution of thrombospondin-specific binding sites and the uptake of thrombospondin-gold conjugates in cultured porcine endothelial cells by light and electron microscopy. Colloidal gold marker and silver enhancement techniques were applied for cytochemical detection of monomeric thrombospondin and fragments of thrombospondin. Thrombospondin binds to granular and fibrillar structures and to sites of cell-cell contact on the cell surface, as indicated by many proteoglycan-cuprolinic blue precipitates. Cell migration tracks on the culture dish bottom are most heavily stained. Labeling of intact thrombospondin and of proteolytic fragments of thrombospondin with colloidal gold followed by silver intensification enables one to detect its binding and uptake in endothelial cells. Binding to the cell surface and uptake of thrombospondin-gold particles was inhibited by heparin but not by hyaluronic acid or chondroitin sulfate. The heparin binding region at the N-terminal end of the thrombospondin molecule proved to be essential for cell surface binding. Gold-conjugated thrombospondin fragments devoid of the heparin binding region were not internalized. After 60 min incubation at 37 degrees C, thrombospondin-gold particles accumulated in the lysosomal compartment close to the nucleus. In the presence of monensin and ammonium chloride, vesicles in this area are swollen and the concentration of particulate marker is reduced. Binding and uptake of thrombospondin by vascular endothelial cells appears to require linkage of the heparin binding region of the thrombospondin molecule to coated pits and heparan sulfate-rich molecules as receptors. Colloidal gold conjugation of thrombospondin fragments proved to be useful for cytochemical characterization of molecular domains.

Ammonium Chloride↗
PubMed1993

Demonstration of anionic sites in human eccrine and apocrine sweat glands in post-embedded ultra-thin sections with cationic colloidal gold: effect of enzyme digestion on these anionic sites.

We localized anionic sites ultrastructurally in human eccrine and apocrine sweat glands with a poly-L-lysine-gold complex (cationic colloidal gold). Anionic sites were labeled by incubating Lowicryl K4M-embedded sections on droplets of cationic colloidal gold. In eccrine sweat glands, colloidal gold particles were restricted to the basolateral membrane of the secretory cells at low pH, whereas the luminal membrane did not react with the gold particles. Chondroitinase ABC digested these anionic sites. This indicates that chondroitin sulfate and/or dermatan sulfate constitutes anionic sites in the basal labyrinth of eccrine sweat glands. In apocrine sweat glands, the luminal membrane of the secretory cells showed strong reaction at low pH, whereas the contraluminal membrane did not show any reaction. Neuraminidase completely digested these anionic sites, which indicated that the anionic charge of the apocrine lumen was due to sialic acid. Differences in distribution and susceptibility to enzymes of anionic sites in cell membranes between eccrine and apocrine sweat glands may reflect functional differences between these glands. Dark cell granules in eccrine secretory cells were negative for the anionic sites when sections were labeled without any pre-treatment. However, pre-incubation of the grids on EGTA or deionized water unmasked the anionic sites on the dark cell granules. The positive staining after EGTA treatment was greatly decreased by reincubation with CaCl2. These results suggested that Ca blocked anionic sites in dark cell granules. Exposed anionic sites were digested with chondroitinase ABC. This indicated that chondroitinase ABC and/or dermatan sulfate composed the anionic sites in dark cell granules.

Anions↗
PubMed2006

Cationic hydrous thorium dioxide colloids--a useful tool for staining negatively charged surface matrices of bacteria for use in energy-filtered transmission electron microscopy.

BACKGROUND: Synthesis of cationic hydrous thorium dioxide colloids (ca. 1.0 to 1.7 nm) has been originally described by Müller 22 and Groot 11 and these have been used by Groot to stain acidic glucosaminoglycans for ultrastructure research of different tissues by conventional transmission electron microscopy. RESULTS: Synthesis of colloidal thorium dioxide has been modified and its use as a suitable stain of acidic mucopolysaccharides and other anionic biopolymers from bacteria, either as whole mount preparations or as preembedment labels, is described. The differences in stain behavior relative to commonly used rutheniumred-lysine and Alcian Blue electron dense acidic stains has been investigated and its use is exemplified for Pseudomonas aeruginosa adjacent cell wall biopolymers. For the first time thorificated biopolymers, i.e. bacterial outer cell wall layers, have been analysed at the ultrastructural level with electron energy loss spectroscopy (EELS) and electron spectroscopic imaging (ESI), leading to excellent contrast and signal strength for these extracellular biopolymers. CONCLUSION: Application of cationic hydrous ThO2 colloids for tracing acidic groups of the bacterial surface and/or EPS has been shown to be rather effective by transmission electron microscopy. Because of its high electron density and its good diffusibility it stains and outlines electro-negative charges within these biopolymers. In combination with ESI, based on integrated energy-filtered electron microscopy (EFTEM) Th-densities and thus negative charge densities can be discriminated from other elemental densities, especially in environmental samples, such as biofilms.

Animals↗
PubMed1977

Electron density and atomic number determination by computed tomography. Part I: Methods and limitations. Part II: A study of colloid cysts.

The feasibility of extracting electron density and effective atomic number from measurements of tissue in vitro and in vivo has previously been reported. The method requires scans to be obtained at two different beam energies. Optimization of these energies at 40 keV and 80 keV could enable a variation of 1 part in 400 of effective atomic number to be detected. The method is subject to certain limitations related to accuracy and sensitivity. The effect of varying the concentrations of certain atoms has been modelled demonstrating the limits below which variation in effective atomic number is unlikely to be detectable at acceptable radiation doses. A series of 12 patients with colloid cysts has been considered. All were treated by bilateral ventriculo-cisternostomy from one to 23 years ago. Nine of these patients, and the colloid cyst of one patient who died before treatment could be instituted, have been subjected to double energy scanning. The results suggest that the high attenuation values observed in colloid cysts are due to increased electron density and not to any increase in high atomic number elements. The cysts do not appear to change in size or content over long periods.

Adult↗
PubMed2006

Fabry-Perot etalons using colloidal photonic crystal mirrors.

Fabry-Perot etalons have been fabricated with 3D colloidal photonic crystal mirrors. The colloid films were optimized for high reflection and low loss to provide good finesse values in the 1200-1700 nm spectral range. A cavity quality factor of 2400 and a finesse of 8 together with sharp 0.5 nm wide resonance transmission peaks are reported that attest to the relatively good optical quality of the three-dimensionally structured films and the promise of self-assembly colloidal crystal chemistry in providing novel microporous optical interferometers for potential applications such as environmental and biological sensing.

Journal Article↗
PubMed1977

Colloid osmotic pressure as a prognostic indicator of pulmonary edema and mortality in the critically ill.

The relationship of colloid osmotic pressure (COP) to pulmonary edema and mortality in 128 critically ill patients was investigated in our critical care unit, and confirms previously reported observations. The COP in the 86 survivors was 22.0 (+/- 0.4 SEM) mm Hg versus 17.2 (+/- 0.6 SEM) mm Hg in the 42 who died (P less than 0.001). The patients were divided into three groups: 71 with no pulmonary edema, COP of 21.5 (+/- 0.5 SEM) mm Hg; 40 with cardiogenic pulmonary edema, COP of 21.4 (+/- 0.4 SEM) mm Hg; and 17 with noncardiogenic pulmonary edema, COP OF 13.6 (+/- 0.8 SEM) mm Hg. Colloid osmotic pressure was significantly lower in patients with noncardiogenic pulmonary edema (P less than 0.001). In 36 patients in whom pulmonary artery wedge pressures (PWP) were available, a COP-PWP gradient of 4.0 mm Hg or less was always associated with pulmonary edema, while a COP-PWP gradient greater than 4.0 mm Hg was never associated with pulmonary edema. Colloid osmotic pressure is a useful prognostic indicator of pulmonary edema and mortality in the critically ill.

Adolescent↗
PubMed2004

Colloid surface chemistry critically affects multiple particle tracking measurements of biomaterials.

Characterization of the properties of complex biomaterials using microrheological techniques has the promise of providing fundamental insights into their biomechanical functions; however, precise interpretations of such measurements are hindered by inadequate characterization of the interactions between tracers and the networks they probe. We here show that colloid surface chemistry can profoundly affect multiple particle tracking measurements of networks of fibrin, entangled F-actin solutions, and networks of cross-linked F-actin. We present a simple protocol to render the surface of colloidal probe particles protein-resistant by grafting short amine-terminated methoxy-poly(ethylene glycol) to the surface of carboxylated microspheres. We demonstrate that these poly(ethylene glycol)-coated tracers adsorb significantly less protein than particles coated with bovine serum albumin or unmodified probe particles. We establish that varying particle surface chemistry selectively tunes the sensitivity of the particles to different physical properties of their microenvironments. Specifically, particles that are weakly bound to a heterogeneous network are sensitive to changes in network stiffness, whereas protein-resistant tracers measure changes in the viscosity of the fluid and in the network microstructure. We demonstrate experimentally that two-particle microrheology analysis significantly reduces differences arising from tracer surface chemistry, indicating that modifications of network properties near the particle do not introduce large-scale heterogeneities. Our results establish that controlling colloid-protein interactions is crucial to the successful application of multiple particle tracking techniques to reconstituted protein networks, cytoplasm, and cells.

Actins↗
PubMed1989

Antibodies to 'second colloid antigen.' A study on the prevalence in sporadic forms of congenital hypothyroidism.

Antibodies against the so called 'second colloid antigen' (CA2 antibodies) occurred in 51% of the mothers of hypothyroid children detected by screening for neonatal congenital hypothyroidism in Quebec (N = 49) and in The Netherlands (N = 26). In The Netherlands where corresponding neonatal serum was available, 31% (8 of 26) of the infants with congenital hypothyroidism were positive for antibodies against the second colloid antigen. When during follow-up, 3 to 5 years after diagnosis, the mothers and their children were investigated, 46% (7 of 15) of the mothers were positive for antibodies against the second colloid antigen, whereas 29% (4 of 14) of the hypothyroid children were also positive. Various control groups did not show more than a 12% positivity. This presence of thyroid-reactive antibodies in a proportion of the hypothyroid children 3 to 5 years after diagnosis is not compatible with a mere transplacental passage; it indicates that the antibodies must be produced by the mothers and by the children themselves. We conclude that a thyroid autoimmune response occurs in a considerable part of infants with congenital hypothyroidism and their mothers and that this immune response seems to persist in both of them for years.

Adult↗
PubMed2006

A novel colloid probe preparation method based on chemical etching technique.

Several fundamental problems in hydrophobic force measurements using atomic force microscope (AFM) are discussed in this paper. A novel method for colloid probe preparation based on chemical etching technology is proposed, which is specially fit for the unique demands of hydrophobic force measurements by AFM. The features of three different approaches for determining spring constants of rectangular cantilevers, including geometric dimension, Cleveland and Sader methods are compared. The influences of the sizes of the colloids on the measurements of the hydrophobic force curves are investigated. Our experimental results showed that by selecting colloid probe with proper spring constant and tip size, the hydrophobic force and the complete hydrophobic interaction force curve can be measured by using AFM.

Journal Article↗