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Biomedical subjects

A Dekker

Publications and source records attributed to A Dekker.

At least 91 records · Page 5Linked to original sources
PubMed1987

Liver transplant rejection: angiographic findings in 35 patients.

Rejection, the leading cause of liver allograft dysfunction, is usually detected by liver biopsy. The purpose of this study was to determine if there are angiographic findings that correlate with this posttransplantation complication. In a retrospective study, the angiograms of 35 patients with histologically proven allograft rejection were reviewed. The examinations were done because of suspected posttransplantation vascular complications. Abnormal hepatic arteriograms were observed in 30 (86%). Eleven (37%) of the 30 had hepatic artery thrombosis (all had acute rejection). Nineteen (63%) of the 30 had varying degrees of intrahepatic arterial narrowing (14 had acute and five had chronic rejection). Additional findings in patients with acute rejection included stretching of the intrahepatic arterial tree (five cases) and slow flow, poor peripheral arterial filling, and a decrease in the number of intrahepatic arteries (10 cases total). Intrahepatic branch vessel stenoses and occlusions were seen in four patients with chronic rejection. We conclude that there is good correlations between the angiographic findings and histologic evidence of rejection. Although angiography is not advocated as a test for transplant rejection, detection of certain findings raises the possibility of rejection.

Adult↗
PubMed1986

Constrictive pericarditis mimicking Budd-Chiari syndrome.

Budd-Chiari syndrome and constrictive pericarditis share many clinical and histologic features. Clinicians must continue to reassess patients when given histologic data that are not specific for a particular disease entity, so that subtle clinical differences are recognized, appropriate diagnosis made, and therapy instituted.

Adult↗
PubMed1986

Effects of phorbol esters on metabolic variables in the thyroid.

Since 12-O-tetradecanoyl-phorbol-13-acetate (TPA) reproduced some of the effects of TSH on phosphorylation of polypeptides in the thyroid, its effects on several thyroid metabolic variables were investigated. Like TSH, TPA stimulated glucose oxidation, iodide organification, and 32P incorporation into phospholipids in thyroid slices. However, in contrast to TSH, it did not augment cAMP accumulation. An inactive phorbol ester, 4 alpha-phorbol, did not reproduce any of the effects of TPA. An initial incubation of thyroid slices with TPA decreased the stimulation of cAMP, glucose oxidation, and colloid droplet formation induced by TSH. However, an initial incubation with TPA did not modify the subsequent stimulation of glucose oxidation induced by (Bu)2 cAMP. TPA potentiated the ability of TSH to desensitize the adenylate cyclase system. Although both TPA and TSH increased 32P incorporation into phospholipids, the patterns were different when individual phospholipids were examined. These results indicate another regulatory mechanism for thyroid cell functions independent of cAMP.

Animals↗
PubMed1985

Orbital fine-needle aspiration biopsy.

Fine-needle aspiration was used as a primary orbital diagnostic technique in 156 patients. A 20-mm syringe, a 22-gauge, 3.75-cm needle, and a plastic pistol grip were used. Local anesthetic was not necessary. When the needle is in the lesion, small to-and-fro movements with a minimum of angulation are helpful. The aspirate is spread on slides fixed with alcohol. Positive cytologic identification was made in 125 of 156 cases. Commonly identified lesions included metastatic carcinoma, inflammatory lesions, and lymphoid lesions. Small posterior apical lesions are difficult to aspirate, but are often the most rewarding diagnostically. Fine-needle aspiration was not successful in tumors of fibrous consistency, in those located in the orbital apex, or in lymphocytic lesions with specimens inadequate for diagnosis.

Biopsy, Needle↗
PubMed1985

Uptake and transport of intact macromolecules in the intestinal epithelium of carp (Cyprinus carpio L.) and the possible immunological implications.

Two protein antigens, horseradish peroxidase (HRP) and ferritin, have been administered to the digestive tract of carp. Electron-microscopical observations reveal considerable absorption of both antigens in the second segment of the gut (from 70 to 95% of the total length) and also, although to a lesser extent, in the first segment (from 0 to 70% of the total length). Even when administered physiologically with food, a large amount of ferritin is absorbed by enterocytes in the second gut segment. HRP and ferritin are processed by enterocytes in different ways. HRP seems to adhere to the apical cell membrane, probably by binding to receptors, and is transported in vesicles to branched endings of lamellar infoldings of the lateral and basal cell membrane. Consequently, most of the HRP is released in the intercellular space where it contacts intra-epithelial lymphoid cells. Only small amounts of HRP become localized in secondary lysosomes of enterocytes. Ferritin does not bind to the apical cell membrane; after uptake by pinocytosis, it is present in small vesicles or vacuoles that appear to fuse with lysosome-like-bodies. In the second segment, intact ferritin ends up in the large supranuclear vacuoles (after 8 h), where it is digested slowly. Although no ferritin is found in the intercellular space, ferritin-containing macrophages are present between the epithelial cells, in the lamina propria and also to a small extent in the spleen. The transport of antigens from the intestinal lumen, through enterocytes, to intra-epithelial lymphoid cells or macrophages may have immunological implications, such as induction of a local immune response and prospectives for oral vaccination.

Animals↗
PubMed1985

Pathology of hepatic transplantation: A review of 62 adult allograft recipients immunosuppressed with a cyclosporine/steroid regimen.

The pathologic specimens (n = 118) and hospital course pertinent to each of 62 adult liver allograft recipients were reviewed. Biopsies and retransplanted organs were obtained at the discretion of the surgical team on the basis of the postoperative clinical course (less than 1 day to greater than 12 years after transplantation), and final interpretation of the pathologic material was based on a correlation of all available data. Most of the specimens (n = 85) were obtained within the first 2 months, and diagnoses in this time period included rejection, biliary obstruction/cholangitis, vascular injury, herpesvirus and cytomegalovirus hepatitis, graft necrosis, and functional cholestasis. Thereafter, rejection and recurrent or primary viral hepatitis were the major causes of graft dysfunction. Histologically, hepatic rejection is manifested by a cellular mediated injury of hepatocytes and bile ductules and a spectrum of vascular lesions in medium-sized hilar arteries. Morphologic changes of biliary duct obstruction and viral liver disease were at times difficult to differentiate from rejection. Two pretransplant disorders, type B viral hepatitis and the Budd-Chiari syndrome, recurred in grafted organs. Although interpretation of pathologic material may be difficult at times, it frequently is helpful in planning an approach to management of liver allograft recipients.

Adolescent↗
PubMed1984

The DNA sequence of the nuclear gene coding for the 17-kd subunit VI of the yeast ubiquinol-cytochrome c reductase: a protein with an extremely high content of acidic amino acids.

We have determined the DNA sequence of the nuclear gene coding for the 17-kd subunit VI of the ubiquinol-cytochrome c reductase. The reading frame found encodes a putative polypeptide of 17 394 daltons. This protein is highly unusual: 38% of its residues are acidic and 14% are basic amino acids. The most notable feature in the protein sequence is a stretch of 25 consecutive acidic amino acids. The polypeptide has homology with the 9-kd so-called 'hinge' protein of beef-heart complex III, which also has a cluster of acidic residues. Acidic amino acids are likely to be essential for the function of these proteins, since their degree of conservation is higher than that of other residues.

Amino Acid Sequence↗
PubMed1984

Functioning oxyphil cell adenoma of the parathyroid gland: a clinicopathologic study of ten patients with hyperparathyroidism.

Adenomas of the parathyroid gland, the majority of which are of the solitary chief cell type, are the most frequent cause of primary hyperparathyroidism. Parathyroid adenomas composed predominantly or exclusively of oxyphil cells are rare and were previously considered nonfunctioning. Among 160 consecutive patients with primary hyperparathyroidism who were explored surgically, ten (6.25 per cent) had adenomas of the oxyphil cell variety. The eight women and two men in this series ranged in age from 28 to 82 years (average, 58 years). The tumors weighed from 0.2 to 4.0 g (average, 1.2 g). Nine of the adenomas were located in the left neck, while the remaining tumor was in the right neck. Histologically, the tumors were composed almost exclusively of transitional and typical oxyphil cells. A residual "capsular" parathyroid composed of chief cells was identified in each case. Electron microscopy, phosphotungstic acid-hematoxylin staining, and the immunoperoxidase technique for cytochrome c oxidase showed the presence of numerous mitochondria in oxyphil cells. All patients had normal serum calcium levels four months to four years (average, 23 months) after removal of the neoplasms.

Adenoma↗
PubMed1984

Recognition of Pneumocystis carinii by gram stain in impression smears of lung tissue.

In 12 of 20 (60%) biopsy-proven cases of Pneumocystis carinii pneumonia, the diagnosis was first suggested by examination of routine Gram stains of impression smears made from infected lung tissue and later confirmed by methenamine-silver staining. The cysts appeared as 5- to 7-microns unstained spheres, each containing six to eight intracystic gram-negative bodies (sporozoites). Although the Gram stain does not appear to be as sensitive as more traditional staining techniques for the detection of P. carinii, clinical microbiologists should be aware of the morphology of this organism in gram-stained specimens because this relatively simple procedure gives quick results.

Humans↗
PubMed1984

Accuracy of computerized tomography in determining hepatic tumor size in patients receiving liver transplantation or resection.

Computerized tomography (CT) of liver is used in oncologic practice for staging tumors, evaluating response to treatment, and screening patients for hepatic resection. Because of the impact of CT liver scan on major treatment decisions, it is important to assess its accuracy. Patients undergoing liver transplantation or resection provide a unique opportunity to test the accuracy of hepatic-imaging techniques by comparison of findings of preoperative CT scan with those at gross pathologic examination of resected specimens. Forty-one patients who had partial hepatic resection (34 patients) or liver transplantation (eight patients) for malignant (30 patients) or benign (11 patients) tumors were evaluable. Eight (47%) of 17 patients with primary malignant liver tumors, four (31%) of 13 patients with metastatic liver tumors, and two (20%) of 10 patients with benign liver tumors had tumor nodules in resected specimens that were not apparent on preoperative CT studies. These nodules varied in size from 0.1 to 1.6 cm. While 11 of 14 of these nodules were less than 1.0 cm, three of 14 were greater than 1.0 cm. These results suggest that conventional CT alone may be insufficient to accurately determine the presence or absence of liver metastases, extent of liver involvement, or response of hepatic metastases to treatment.

Adenoma, Bile Duct↗
PubMed1983

Simple determination of oxime carbamates in soil and environmental water by high pressure liquid chromatography.

A method for determining residues of aldicarb, aldicarb sulphoxide, aldoxycarb, oxamyl and methomyl in soil, groundwater and surface water is described. Subsoils were extracted with water and topsoils were extracted with acetone. The aqueous samples were either directly injected after acidification or concentrated by extraction with chloroform. The organic extracts were evaporated to dryness and redissolved in acidified mobile phase. The compounds were detected with a variable wavelength U.V. detector or with a fluorometric detector after a post-column reaction. Compounds within a concentration range from 0.5 ng/ml to 200 micrograms/ml could be determined with a maximum coefficient of variation of 7.5%. Recoveries varied from 77.0% to 98.8%.

Carbamates↗
PubMed1983

Orbital fine-needle aspiration biopsy in patients with cavernous sinus syndrome.

The authors report their experience with five patients presenting with cavernous sinus syndrome who, on computerized tomography (CT) studies, were shown to have a lesion simultaneously involving the cavernous sinus and a portion of the orbit. All patients underwent an orbital fine-needle aspiration biopsy (FNAB). A specific cytological diagnosis was made in three of the five patients. To obtain pathological diagnosis in the case of cavernous sinus tumors, invasive diagnostic procedures are sometimes necessary. Extension of lesions from the cavernous sinus into adjacent areas should be carefully looked for on CT scans. In the specific subset of patients with cavernous sinus tumors and simultaneous orbital involvement, orbital FNAB may provide a simple alternative to more invasive procedures. The limitations of the procedure are discussed.

Adenocarcinoma↗
PubMed1983

The black thyroid. Its relation to minocycline use in man.

We studied a patient with a grossly black thyroid gland considered to be related to minocycline therapy. Microscopically, a brown granular pigment was localized in follicular cells and colloid, which histochemically was melanin or a melaninlike substance. Ultrastructurally, the pigment is confined to lysosomes. The pigment seems to be either an oxidative degradation product of the drug itself, or the results of an as yet unknown alteration of tyrosine metabolism by the drug. Although minocycline is known to interfere with thyroid function in animals, no evidence has been presented for such an effect in humans. The occurrence of a black thyroid gland in humans seems to be virtually pathognomonic for long-term minocycline therapy.

Humans↗
PubMed1983

Budd-Chiari syndrome recurring in a transplanted liver.

A patient with Budd-Chiari syndrome who underwent orthotopic liver transplantation and developed recurrent disease is described. The immediate postoperative period was complicated by multiple thrombotic episodes, followed by a period of apparent remission associated with the initiation of coumadin and persantine therapy. After discontinuation of such antithrombotic therapy in order to biopsy the liver, the patient experienced another series of clinically overt vascular thromboses and ultimately died of sepsis 15 mo posttransplantation after a prolonged and complicated terminal hospital course. At autopsy, recurrent Budd-Chiari syndrome as well as thromboses in numerous other organs was demonstrated.

Adult↗
PubMed1983

Relationship between cell size and weight of the human liver. An automated morphometric study.

Using a machine-vision system for the analysis of multicolor multicellular images, an algorithm, consisting of cellular logic operators, was developed for estimating the average cross-sectional area of cells in the liver. A total of 28 three-color histologic images from 22 variable-weight autopsied livers were digitized and processed. The data collected showed a positive correlation, albeit weak, between the weight of the liver and the cell size. This correlation was not visually evident, which demonstrates the utility of machine vision in histopathology.

Adult↗