Cecal inflammatory fibroid polyp presenting with chronic diarrhea. A case report and review of the literature.
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Adult↗
Biomedical subjects
A Dekker
Publications and source records attributed to A Dekker.
Hemoperitoneum in the setting of metastatic cancer to the liver. A report of two cases with review of the literature.
Two cases of hemoperitoneum occurring as a result of hepatic rupture due to metastatic neoplasms are presented. They represent examples of a striking and devastating but fortunately uncommon entity. The variety of primary neoplastic sites is diverse. Several possible mechanisms have been put forward to explain the event of hepatic rupture itself. Finally, it is important to note the uniformly poor survival rates following hepatic rupture despite therapy.
Adenocarcinoma↗
Improved adhesion and proliferation of human endothelial cells on polyethylene precoated with monoclonal antibodies directed against cell membrane antigens and extracellular matrix proteins.
Endothelial cell seeding may improve the patency of synthetic vascular grafts provided that platelet reactivity of nonendothelialized sites is not increased. We have investigated if surface-adsorbed monoclonal antibodies directed against endothelial cell membrane proteins and against extracellular matrix proteins promote the adhesion and proliferation of cultured human endothelial cells, without causing platelet deposition at non-endothelialized sites. Adhesion of endothelial cells onto polyethylene coated with monoclonal antibodies directed against endothelial cell-specific membrane antigens, integrin receptors and glycoprotein CD31 was equal to or higher than adhesion onto fibronectin-coated polyethylene. Endothelial cells did not proliferate on these surface-adsorbed antibodies. However, pre-coating of polyethylene with mixtures of endothelial cell-specific monoclonal antibodies and monoclonal antibodies directed against fibronectin or von Willebrand factor, resulted in relatively high adhesion and optimal proliferation. Platelet reactivity of the polyethylene surface was found to significantly increase after adsorption of fibronectin, endothelial cell-specific monoclonal antibody or its Fc fragments. In contrast, adsorption of F(ab')2 fragments of endothelial cell-specific monoclonal antibody did not promote platelet deposition. Therefore, it is concluded that coating of vascular graft materials with mixtures of F(ab')2 fragments of monoclonal antibodies specifically directed against endothelial cells and against extracellular matrix proteins may be an effective way to both promote the growth of seeded endothelial cells and limit platelet-graft interaction.
Adsorption↗
Vascular entrapment of intra-aortic balloon after short-term balloon counterpulsation.
Prolonged, continuous intra-aortic balloon (IAB) counterpulsation for several weeks can result in balloon entrapment secondary to thrombus formation in the balloon lumen. In this report, we describe a patient who developed IAB entrapment, early (1 wk) after initiation of counterpulsation. A trace amount of blood was noted in the tubing connecting the balloon catheter to the console for 3 days prior to IAB malfunction and vascular entrapment. We suggest that the balloon catheter be removed immediately when blood is detected in the external connecting tubing even if the IAB is functioning satisfactorily.
Adult↗
Usefulness of a near-total fine-needle aspiration biopsy retrieval method: a study of its use in 85 consecutive patients.
Fine-needle aspiration biopsy may provide miniscule material for diagnosis. A method was devised to ensure optimal retrieval of the specimen. If performed in the manner described, at least four to five different samples from each case may be obtained. This includes a smear stained with the Papanicolaou and hematoxylin and eosin methods, a cell block preparation, and at least two cytocentrifuge specimens. In 85 cases in which the method was applied and subsequently analyzed, we found the cell block and Papanicolaou-stained smears to be most effective for diagnosis, whereas the cytocentrifuge method was much less effective. The sensitivity and specificity were 93% and 100%, respectively.
Aged↗
Adhesion of endothelial cells and adsorption of serum proteins on gas plasma-treated polytetrafluoroethylene.
From in vitro experiments it is known that human endothelial cells show poor adhesion to hydrophobic polymers. The hydrophobicity of vascular prostheses manufactured from Teflon or Dacron may be the reason why endothelialization of these grafts does not occur after implantation in humans. We modified films of polytetrafluoroethylene (Teflon) by nitrogen plasma and oxygen plasma treatments to make the surfaces more hydrophilic. Depending on the plasma exposure time, modified polytetrafluoroethylene surfaces showed water-contact angles of 15-58 degrees, versus 96 degrees for unmodified polytetrafluoroethylene. ESCA measurements revealed incorporation of both nitrogen- and oxygen-containing groups into the polytetrafluoroethylene surfaces, dependent on the plasma composition and exposure time. The thickness of the modified surface layer was approximately 1 nm. The adhesion of cultured human endothelial cells from 20% human serum-containing culture medium to modified polytetrafluoroethylene surfaces with contact angles of 20-45 degrees led to the formation of a monolayer of cells, which was similar to the one formed on tissue culture polystyrene, the reference surface. This was not the case when endothelial cells were seeded upon unmodified polytetrafluoroethylene. Surface-modified expanded polytetrafluoroethylene prosthesis material (GORE TEX soft tissue) also showed adhesion of endothelial cells comparable to cell adhesion to the reference surface. The amounts of serum proteins, including fibronectin, adsorbed from serum-containing medium to modified polytetrafluoroethylene surfaces were larger than those adsorbed to unmodified polytetrafluoroethylene. Moreover, the modified surfaces probably allow the exchange of adsorbed serum proteins with cellular fibronectin.
Adsorption↗
Diagnostic value of DNA analysis in effusions by flow cytometry and image analysis. A prospective study on 102 patients as compared with cytologic examination.
One hundred twenty-six effusion samples from 102 patients were examined by cytology and flow cytometry (FCM). Overall, there was an 84% correlation between cytologic and FCM results. Of the 36 malignant cases determined by cytologic examination, FCM revealed an aneuploid peak in 20 (56%). Image analysis (IA) performed on the malignant cytologic cases with a diploid flow pattern detected two additional aneuploid peaks. In addition, FCM indicated three aneuploid cases in which cytologic characteristics were initially interpreted as benign (false negative). Aneuploidy was therefore detected in 64% of the malignant effusion specimens by FCM and IA. Twenty-three of the total of 24 aneuploid cases detected by FCM were associated with malignancy (predictive value = 96%). The one nonmalignant case was that of hemorrhagic pancreatitis with infected pseudocyst. FCM is an excellent tool when moderate to large numbers of tumor cells are present, whereas use of IA is advantageous for specimens containing smaller numbers of malignant cells because these can be directly analyzed. When an aneuploid peak is present, a diagnosis of malignancy must be suspected, and, if the initial cytologic screen is negative, a critical review of the cytology slides is justified. In those cases with an equivocal atypical cytology report and an abnormal cytometric histogram, additional investigation is warranted. In some malignancies the tumor cells will be diploid (in this study 36%) and neither FCM nor IA will add to tumor detection, leaving cytologic examination as the definitive technique.
Adult↗
Pneumocystis carinii infection presenting as necrotizing thyroiditis and hypothyroidism.
Extrapulmonary Pneumocystis infection has been increasingly reported in patients with acquired immune deficiency syndrome (AIDS), in particular, recently in association with the increasing use of aerosolized pentamidine. This report describes the unusual presentation of extrapulmonary Pneumocystis infection as a thyroid neck mass and clinical hypothyroidism in a 37-year-old man with hemophilia and AIDS. This case differs from the previously reported single case of isolated thyroid pneumocystosis in the presence of a rapidly enlarging neck mass, lack of previous Pneumocystis, and prior prophylaxis with aerosolized pentamidine. The pathologic and electron microscopic description of the peculiar flocculent necrotic thyroid material is contrasted with typical pulmonary alveolar findings in Pneumocystis pneumonia (PCP), the differential diagnoses of a rapidly expanding neck mass, and diagnostic difficulties of hypothyroidism in patients with AIDS are discussed. Finally, it is emphasized that use of aerosolized pentamidine, although successful for prevention of pulmonary PCP, may be insufficient to prevent extrapulmonary infection.
Acquired Immunodeficiency Syndrome↗
Diagnostic value of brush cytology in the diagnosis of bile duct carcinoma: a study in 65 patients with bile duct strictures.
Malignant strictures of the extrahepatic bile ducts are difficult to distinguish from benign strictures, particularly in patients with primary sclerosing cholangitis. Because attempts at diagnosing small cancers with fine-needle aspiration biopsy are not possible in the absence of an associated mass lesion and because the sensitivity of exfoliative biliary cytology is controversial, brush cytology has been used as a potential means of establishing a specific diagnosis of bile duct carcinoma. Herein we report our experience with this technique when performed on 65 patients over a 5-yr period. Each had at least one brushing. Thirty-seven were found to have bile duct carcinoma and 28 were found to have benign strictures. Of these 37, the first brushing was positive for malignancy in 15 (40%), whereas four (11%) had cells suspected but not diagnostic of malignancy. Thirteen patients with bile duct carcinoma whose initial brushings were negative for malignancy had second brushings. Of these, five (38%) had malignant cells, whereas three (24%) yielded suspicious cells. Three of the eight whose first two brushings were negative for malignancy were found to have malignant cells on the third brushing. In contrast, of the 28 patients with benign strictures, malignant cells were never found. However, in two patients, suspicious cells were reported with the first but not the second brushing. A single negative or suspicious cytological finding decreased the probability of bile duct carcinoma to 43%. Two and three sequential negative tests reduced the probability to 32% and 0%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Reversibility of ganglioside effects on astrocyte morphology.
The B-subunit of cholera toxin (BCT) induces a morphological change in cultured rat cerebral astrocytes from flat (epithelioid) to stellate (process-bearing). This stellation is reversed by the gangliosides GM1 and GD1a at concentrations of 10 microM or higher. Upon changing to a ganglioside-free medium, the flat astrocytes reacquire the stellate morphology within 3 hr, indicating that the antistellation effect of gangliosides is reversible. The possibility that this reversibility was due to a loss of exogenously acquired gangliosides from the cell membrane can be ruled out since pretreatment with GM1, but not GD1a, which does not bind BCT, results in an increased responsiveness to BCT, which was identical whether measured immediately after withdrawal of the ganglioside or 3 hr later. Asialo-GM1, which neither binds BCT nor reverses BCT-induced stellation by itself, prevents the return to stellation after withdrawal of the gangliosides. These data suggest that while gangliosides remain associated with the cell, their effect on astrocytes can change from opposing to permitting the stellate morphology.
Animals↗
Additional psychiatric insight into chronically ill adolescents.
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Adolescent↗
The effect of vascular cell seeding on platelet deposition in an in vitro capillary perfusion model.
In view of the reported beneficial effects of cell seeding on the performance of synthetic vascular grafts, we determined the deposition of 111Indium-labelled human platelets in polyethylene capillary tubes covered with human endothelial cells (HEC) or smooth muscle cells (SMC) using an in vitro perfusion model. Platelet deposition decreased with increasing vascular cell coverage and was virtually absent when the number of adherent vascular cells of both types exceeded 50,000/cm2. Platelet deposition increased with increasing shear rate (300-900 s-1) only when surface coverage was less than 50,000 vascular cells/cm2. Deposition of Ca2+-ionophore A 23187-activated platelets in capillary tubes completely covered with SMC was significantly higher compared to capillaries covered with a similar number of HEC. When HEC-lined capillaries were treated with aspirin, only the deposition of activated platelets increased slightly, but significantly. This platelet reactivity was more evident when the endothelial lining was not confluent. These results demonstrate that, although seeding of HEC and SMC may both prevent the deposition of non-activated platelets to surfaces, non-aspirin-treated confluent HEC linings offer the best protection against deposition of activated platelets.
Aspirin↗
Cholangiocarcinoma associated with multiple bile-duct hamartomas of the liver.
The case of a 61-year-old woman with a surgically resected solitary cholangiocarcinoma of the liver is reported, where many discrete multiple bile duct hamartoma (MBDH) were also seen. The latter is a congenital lesion of the liver that potentially may be confused with widespread metastatic disease. The relationship between cholangiocarcinoma and MBDH was studied histologically by the use of an immunoperoxidase technique for cytokeratin. MBDH was strongly positive for cytokeratin, while the neoplasm showed this to a lesser extent, but a clear continuity between the MBDH epithelial cells and those of the neoplasm was demonstrated by the use of this technic. The potential use for the various cytokeratins in the differentiation of primary from secondary liver tumors, is discussed. This differentiation is a significant problem to the pathologist. Although cholangiocarcinoma may, on occasion, be associated with various congenital lesions of the bile ducts, the association with MBDH is extremely rare, this being only the third reported case.
Adenoma, Bile Duct↗
An improved device for continuous intraventricular infusions prevents the introduction of pump-derived toxins and increases the effectiveness of NGF treatments.
The recent demonstrations of the ability of nerve growth factor (NGF) to protect and promote the welfare of certain cholinergic neurons in the adult CNS have increased the need for safe, accurate, and reliable procedures for intracerebral administration of protein and other experimental agents. Osmotic minipumps have been used to infuse NGF into the lateral ventricle of adult rats, but a sustained and harmless performance of such infusions has not been fully evaluated. The study reported here has led to (i) the recognition that cytotoxic substances, released from some minipumps into the infusion fluid, may be responsible for various degrees of periventricular tissue damage, and (ii) the redesigning of an infusion device which, among other modifications, uses the osmotic pump to propel infusion fluid into the ventricle but prevents pump-derived materials from entering the infusate itself. Besides several other advantages, the modified infusion device has permitted the demonstration that NGF can fully protect experimentally axotomized medial septum cholinergic neurons and can do so with less variability than previously observed and without creating tissue damage.
Animals↗
Deposition of endothelial fibronectin on polymeric surfaces.
Cellular fibronectin is deposited on tissue culture polystyrene during the adhesion and spreading of cultured human endothelial cells (HEC). Following the seeding of HEC upon this polymer, larger amounts of fibronectin are deposited as both cell density and incubation time increase. Our results indicate that the ability to deposit cellular fibronectin onto a polymeric surface is a condition for the spreading and proliferation of HEC.
Adsorption↗
Rapid detection of cytomegalovirus pneumonia from lung lavage cells.
Because cytomegalovirus (CMV) is a common cause of fatal pneumonia in the immunocompromised host, a rapid and reliable method to confirm this diagnosis is essential. Bronchoalveolar lavage (BAL) has proved to be a rapid, safe, and sensitive method for the diagnosis of several forms of pneumonia in these patients, but its efficacy for confirming CMV pneumonia remains to be established. In this study, we compared the sensitivity and specificity of conventional viral culture, immunocytochemical staining, and cytological examination performed on cells recovered by BAL for establishing CMV as the cause of pneumonia in 71 BAL specimens from 56 immunocompromised patients. Pneumonia due to CMV was confirmed by stated criteria in 14 of these patients. Virus was isolated by culture in BAL specimens from all patients with CMV pneumonia (sensitivity 100%), but also in 17 specimens from patients who did not have CMV pneumonia (specificity 70%). On cytologic examination, CMV inclusions were found in 3 of the 14 specimens from patients with CMV pneumonia (sensitivity 21%) and also in 1 patient at risk for pneumonia but who did not fulfill the criteria (specificity 98%). Thus, a positive culture and positive cytology virtually confirmed CMV pneumonia, whereas a negative culture excluded it. Immunocytochemistry proved to be particularly useful when the culture was positive and cytology was negative. In this situation, specific labeling of CMV antigen by monoclonal antibody was found in 9 of the 11 patients with CMV pneumonia (sensitivity 82%). Thus, the absence of specific staining in BAL cells tended to exclude CMV as a cause of pneumonia in patients with positive cultures and negative cytologies.(ABSTRACT TRUNCATED AT 250 WORDS)
Biopsy↗
Axonal regeneration, growth factors and neuropeptides.
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Adrenocorticotropic Hormone↗
Adsorption of fibronectin derived from serum and from human endothelial cells onto tissue culture polystyrene.
Human endothelial cells (HEC) suspended in a culture medium containing 20% human serum (CMS) adhere and spread on(to) moderately wettable polymers, such as tissue culture polystyrene (TCPS). We have previously shown that serum derived-fibronectin, which is a cell adhesion promoting protein, has a high affinity for TCPS, but that the amount of fibronectin which adsorbed from CMS was relatively small. In this study we investigated whether fibronectin derived from HEC contributes to the adhesion and spreading of the cells on(to) TCPS. Therefore, HEC were seeded in the presence of fibronectin-depleted CMS. The amount of fibronectin detected on TCPS increased with both cell seeding density and incubation time. Although initial HEC adhesion is delayed on TCPS which has been precoated with albumin (Alb), high density lipoprotein (HDL) or immunoglobulin G (IgG), maximal numbers of adhering and spreading HEC were found on these surfaces 6 h after seeding of HEC. Fibronectin was detected on these surfaces, but an exchange of preadsorbed Alb, HDL, or IgG for fibronectin could not be demonstrated. We conclude that HEC deposit fibronectin onto TCPS, irrespective of the presence of a preadsorbed layer of proteins which delay cell adhesion.
Adsorption↗