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1.
The authors report a case of carcinoma in an ex pleomorphic adenoma of the parotid gland that was recently referred to their attention. This form of carcinoma is not very frequent and in the literature it is reported in a percentage of cases ranging from 1.5 to 12%. The pathogenesis of this neoplasia is controversial and at the present state of the art there are authors who support the hypothesis of a malignant transformation of a previous pleomorphic adenoma, and those who sustain the onset of the tumour ex novo. At present, there is a tendency to differentiate the carcinoma ex pleomorphic adenoma from the malignant mixed tumour: the histological analysis of the former in fact shows a benign stromal component typical of pleomorphic adenoma associated with a malignant epithelial component, whereas in the malignant mixed tumour both the mesenchymal and epithelial components are malignant. The authors use this case report as a starting point to review their 20-year experience, of pleomorphic adenoma in order to evaluate the behaviour of this tumour, above all in relation to the phenomenon of recidivation and cancerization. They report recidivation in 3.5% of cases and no malignant degeneration. The surgical approach used varied depending on the site and size of the neoformation, as well as on whether the tumour was primary or recurrent.  相似文献   

2.
In 2 boys aged 8 years and 10 months, respectively, uncommon manifestations of cat scratch disease were seen. The first patient had acute encephalopathy: coma and generalized tonic-clinic convulsions. The second patient was presented with fever and peripheral lymphadenopathy in combination with hypodense lesions in the liver on ultrasound. Diagnosis was established on the clinical picture and the positive results of serological testing of antibody titres for Bartonella henselae. Both patients recovered completely within 2 months.  相似文献   

3.
Pleomorphic adenomas account for the majority of parotid masses, typically arising in the tail of the gland and enlarging slowly over time. The vast majority are 2 to 6 cm in size when resected. We report resection of the largest benign mixed tumor recorded in the modern English language literature. An 85-year-old reclusive woman had a 20-year history of an enlarging right periauricular mass that had begun bleeding several days prior to admission. The patient ultimately underwent resection of the mass, which measured 26 cm in diameter, weighed 6.85 kg, and proved on pathologic examination to be a benign mixed tumor without malignant degeneration. The implications of this unusual case for the management of mixed tumors are discussed, and a review of the world literature on giant pleomorphic adenomas is presented.  相似文献   

4.
1. Human stroke is a complex and heterogeneous phenomenon that may defy attempts to develop a unitary animal model with which to address all of the relevant issues. 2. Focal models are regarded by many to be the approach of choice, but both global and focal models of cerebral ischemia can be sources of useful and complementary insight. 3. Of the global models, four-vessel occlusion requires a preparatory operative procedure that may increase the risk of extraneous factors confounding the response to the ischemic insult itself. The procedures are only partly reversible, with the vertebral arteries remaining permanently occluded. 4. The two-vessel occlusion model is easier to perform in a single procedure, and the less-intrusive surgical intervention allows greater scope for recovery experiments. The occlusion is fully reversible. 5. Many classes of compounds with therapeutic potential have been identified in the laboratory, often on the basis of success in one class of animal model, but translating these successes into a clinical context has proved singularly difficult. If, in future, compounds of interest are tested across a range of the available models, the likelihood of subsequent clinical success may be enhanced.  相似文献   

5.
OBJECTIVES: To determine the incidence of clinical resistance to intraocular cidofovir injection for treatment of acquired immunodeficiency syndrome (AIDS)-related cytomegalovirus (CMV) retinitis, and to identify virologic features associated with cidofovir treatment failure. PATIENTS and METHODS: Clinical resistance to intravitreal cidofovir was examined in 64 patients with CMV retinitis who received at least 1 injection of 20 pg of cidofovir. Histopathologic examination, culture, and polymerase chain reaction were used to detect CMV in ocular specimens. Antiviral resistance was assessed by plaque reduction assay and DNA sequencing. RESULTS: Clinical resistance to intravitreal cidofovir injections was identified in 3 patients (5%) and was associated with prior oral ganciclovir or intravenous cidofovir use. Ganciclovir- and cidofovir-resistant CMV isolates were cultured from 2 patients and harbored resistance-associated mutations in the UL97 and polymerase genes. Resistance mutations were also detected by direct analysis of vitreous. In 1 patient, different resistance mutations were identified in ocular vs extraocular CMV strains. CONCLUSIONS: Clinical failure of intravitreal cidofovir occurs infrequently, but may be associated with cidofovir-resistant CMV selected by prior ganciclovir or cidofovir treatment. Ocular CMV disease can result from a localized infection with a resistant CMV strain, and antiviral resistance may develop at a local site of infection independently from resistance that develops systemically.  相似文献   

6.
The authors, after a survey of the literature, describe the injuries of the facial nerve during parotid surgery for pleomorphic adenoma. The facial nerve damages are often transient with total resolution, except where one or more branches are deliberately sacrificed for malignant tumors or recurrence.  相似文献   

7.
BACKGROUND AND PURPOSE: We investigated the role of actin polymerization in regulating arterial diameter in response to increasing pressure and modulating forced dilatation of cerebral arteries at pressures above the upper limit of autoregulation. METHODS: Posterior cerebral arteries (n = 12) were isolated and pressurized in a special arteriograph that allowed control of intravascular pressure and measurement of lumen diameter. Intact arteries in the absence (control) or presence of 3.0 mumol/L cytochalasin B (CB), an inhibitor of actin polymerization, were subjected to stepwise increases in pressure from 75 to 200 mm Hg. Lumen diameter was continuously recorded, as was the pressure at which forced dilatation (loss of tone) occurred. After a period of time at 200 mm Hg, pressure was returned to 75 mm Hg and the extent of tone recovery was evaluated. RESULTS: Arteries with and without CB developed a similar amount of tone during equilibration at 75 mm Hg: percent tone = 27 +/- 3% for control versus 29 +/- 4% for CB arteries (P > 0.05). However, arteries in the presence of CB could not withstand pressure as well and underwent FD at significantly lower pressures: 168 +/- 5 mm Hg for control versus 142 +/- 5 mm Hg for CB arteries (P < 0.01). The amount of tone that arteries regained after FD when pressure was returned to 75 mm Hg was also less in CB arteries: percent tone = 34 +/- 3% for control versus 11 +/- 2% for CB arteries (P < 0.01). CONCLUSIONS: Cytoskeletal integrity appears important for maintaining cerebral arterial diameter during changing intravascular pressure. In addition, the process of actin polymerization may be a significant contributor to development of myogenic tone after forced dilatation.  相似文献   

8.
We sought to determine if patients with cystic fibrosis and sputum cultures positive for Mycobacterium avium complex (MAC) have delayed-type hypersensitivity to an M. avium sensitin. Seventeen (33%) of 51 selected patients had MAC isolated from at least one sputum culture. Skin tests with purified protein derivative and M. avium sensitin demonstrated that five (10%) of 51 patients were anergic, and anergy was correlated with use of systemic steroids. Sixteen (35%) of 46 nonanergic patients had M. avium-dominant skin test reactions. Twelve (75%) of these 16 patients with cultures positive for MAC had M. avium-dominant skin tests; the specificity of skin testing was 87%. These data suggest that most patients with cystic fibrosis and sputum cultures positive for MAC have infection rather than colonization with MAC. Skin testing with M. avium sensitin is a sensitive and specific method for screening these infections.  相似文献   

9.
This study reports the establishment of alpha-amylase-producing human parotid pleomorphic adenoma cell lines (2HP and 2HP1) which have been maintained in culture for over 1 yr. The procedures required preparation of cellular clumps from tumor tissue and plating them on plasma clot or precoated dishes. During the initial phase of growth they required modified MCDB-153 medium without serum. When cells showed signs of degeneration they were changed to MCDB-153 medium containing first 2% and then 10% heat inactivated fetal bovine serum. Although cells grew well in MCDB-153 containing 10% serum, the epithelial cell morphology was not distinct. Therefore, the growth and morphology of cells grown in MCDB-10% serum were compared with those in RPMI growth medium containing 10% fetal bovine serum and F12 containing 10% agammaglobulin newborn bovine serum. Although the growth of cells was a little slower in F12 medium than those in MCDB and RPMI, the epithelial cell morphology was maintained better than in other growth media. The cells of 2HP and 2HP1 produce low levels of alpha-amylase and relatively high levels of alpha-amylase mRNAs of 1176 and 702 bp and contain neurofilament-160, a neuronal-specific marker. The cells of 2HP1 are tumorigenic when tested in athymic mice, but the cells of 2HP are not. The establishment of amylase-producing human parotid adenoma cell lines of different characteristics in culture provides a new opportunity to study the mechanisms of differentiation and transformation, and regulation of alpha-amylase in these cells.  相似文献   

10.
11.
BACKGROUND: True malignant mixed tumor (carcinosarcoma), composed of carcinoma and sarcoma components, is rare in salivary gland neoplasms. Even rarer is a true malignant mixed tumor arising in the pleomorphic adenoma of the salivary gland. CASE: A 64-year-old male was admitted with left pharyngeal pain. Head and neck magnetic resonance imaging revealed a left parapharyngeal mass; fine needle aspiration (FNA) cytology through the oral cavity was performed. CONCLUSION: The aspirate presented a mixture of large, pleomorphic, vacuolated, single or multinucleated cells in a mucoid matrix and clusters of adenocarcinoma cells. Additionally, occasional benign glandular cells were noted. A cytologic diagnosis of malignant mixed tumor arising in the pleomorphic adenoma of the deep lobe of the parotid gland was made and confirmed by the surgically resected specimen.  相似文献   

12.
Twenty years experience of lateral parotidectomy as suspical treatment for pleomorphic adenoma are reviewed. All cases were managed at the ORL Clinic of the University of Zürich. 167 patients were followed for the frequency of possible recurrent tumors. Three patients (3/123) operated primarily developed a recurrences. Recurrences appeared after an average of 10 years, ranging from 1-30 years. The follow-up time varied from 1 to 21 years (average, 8 years). 39% (13 of 33) of the patients, who were re-operated for a recurrent tumor, developed another recurrence. The second recurrence appeared after an average of 10 years, ranging from 1-22 years. A persistent partial paresis of the facial nerve was found in 1% of the patients operated primarily and in 9% of the patients operated more than once. No paralysis was seen. We now choose "en-bloc" resections of pleomorphic adenomas without intra-operative opening of the tumor capsule as the treatment of choice. This treatment was possible in 83% of all cases, using a lateral parotidectomy. If tumor extends into the medial parotid lobe, total parotidectomy is required.  相似文献   

13.
Hernia repair may involve the use of an implant to augment or replace autologous tissue, but the best material for use in this application has not been established. We developed a dog model to evaluate the mechanical strength of fascial defects repaired using carbon fibers, compared with the strength of similar defects repaired using polypropylene mesh (Marlex). Unrepaired defects were included as an additional control. Bilateral defects (1 cm square) were made in the fascia of the back, and the ultimate mechanical strength and stiffness at the repair sites were measured 3-12 months after operation. Defects repaired with carbon fibers were significantly stronger 12 months after operation compared with defects repaired with polypropylene mesh and compared with unrepaired defects. It is concluded that carbon fibers are biocompatible and significantly increase mechanical strength at the repair site. A randomized clinical trial involving patients undergoing hernia repair seems justified to determine whether carbon fibers are superior to standard therapy.  相似文献   

14.
BACKGROUND & AIMS: The molecular mechanisms responsible for initiation and progression of gastrointestinal mucosa-associated lymphoid tissue (MALT) lymphomas are largely unknown. The aim of this study was to analyze the p16 tumor suppressor gene in MALT lymphomas of the stomach and colon. METHODS: Tumor samples were obtained from 28 patients with low-grade (n = 12) and high-grade (n = 14) gastric MALT lymphomas and from 2 patients with colonic MALT lymphomas. DNA was extracted from microdissected areas with at least 80% tumor cells. To detect homozygous p16 deletions, a semiquantitative polymerase chain reaction assay was used, whereby either p16 exon 1 or exon 2 was coamplified with an unrelated sequence as internal control. RESULTS: Homozygous p16 deletions were found in 2 of 14 (14%) cases with high-grade gastric MALT lymphomas. Both patients had Helicobacter pylori-associated gastritis; however, DNA extracted from areas of gastritis showed a normal p16 complement. No deletion was found in any of the low-grade gastric or the colonic MALT lymphoma specimens. CONCLUSIONS: In a subset of gastric MALT lymphomas, homozygous p16 deletions are acquired and may contribute to the transformation from a low-grade to a high-grade malignancy.  相似文献   

15.
BACKGROUND: In a previous study, it was shown that a spontaneously tolerated DA (RT1a) liver allograft in a PVG (RT1c) recipient was able to induce tolerance of a DA small bowel graft performed 17 days later in spite of infiltration of the intestinal grafts by mononuclear cells. AIMS: To compare the phenotype of graft infiltrating cells in rejecting and tolerated small bowel grafts in order to elucidate the mechanism(s) which block the graft infiltrating cells from mediating rejection. METHODS: Multiparameter immunofluorescence was used to compare the phenotype and state of activation of donor and recipient cells isolated from intestinal grafts rejected or tolerated after liver transplantation. RESULTS: Three differences were found. Firstly, there was a more rapid replacement of lamina propria (LP) cells by recipient lymphocytes in tolerated than in rejected grafts. Secondly, the proportion of LP recipient CD8alphabeta+ lymphocytes bearing the high affinity receptor for interleukin 2 was significantly less in tolerated grafts (1.1%, range 0-2%) than in rejected grafts (21.3%, range 9-26%). Finally, tolerated grafts contained significantly less NK lymphocytes (NKR-P1+) and macrophages than rejected intestinal allografts. CONCLUSIONS: These observations make it possible to delineate clear cut differences in the phenotype of cells infiltrating rejecting versus tolerated grafts. Furthermore, the data suggest that liver transplantation induces tolerance of intestinal grafts by hampering the activation of recipient TcRalphabeta+ CD8alphabeta+ T cells and subsequently the recruitment of non-specific effector cells.  相似文献   

16.
An adult male diver developed limb pains and peripheral neurologic signs following a series of dives. He was treated for acute neurologic decompression illness (DCI) and responded well, but subsequently he deteriorated and developed features of a progressive multisystem disease. Investigation confirmed a clinical diagnosis of polyarteritis nodosa complicated by a mononeuritis multiplex. Vasculitis is uncommon and its masquerade as neurologic DCI may be unique. However, this case empha-sizes the importance of careful clinical assessment and illustrates the potentially wide differential diagnosis of DCI.  相似文献   

17.
18.
OBJECTIVE: To study the molecular defects of congenital adrenal hyperplasia (CAH). STUDY DESIGN: Twenty Chinese patients, including 8 with salt-wasting (SW) type CAH, 11 with simple virilizing (SV) type CAH and 1 with nonclassical (NC) type CAH, were recruited. Two rounds of the polymerase chain reaction (PCR) were used to study the 21-hydroxylase gene (CYP21). The primary PCR amplified CYP21-specific DNA fragments, and the secondary PCR used products from the primary PCR for analysis of amplification-created restriction sites (ACRS) and direct DNA sequencing. In all patients, ACRS analysis was done at 12 possible mutation sites, and then direct DNA sequencing was performed to confirm or define the molecular defects. RESULTS: Ten different mutations, including nine point mutations and gross gene deletion or conversion, were found in this study. Of the nine point mutations, eight could be easily detected by ACRS analysis. The three most common mutations were codon (CD)172 t-->a (I172N), IVS-II 656 c/a-->g, and gross gene deletion or conversion, accounting for 27.5% (11/40 alleles), 25% (10/40) and 20% (8/40) of all identified mutations, respectively. All SW patients were compound heterozygotes of IVS-II 656, gross gene deletion or conversion, or other severe defects, including CDs236 (t-->a) (I236N)+ 237 (t-->a) (V237E)+ 239 (t-->a) (M239K), CD306 (+t), CD318 (c-->t) (Q318X) and CD356 (c-->t) (R356W) mutations. All SV patients had one allele with a CD172 (I172N) mutation. One allele of an NC patient had a CD183 (c-->g) (D183E) mutation, and the other allele was not defined. In the whole series, four alleles (10%) had more than one mutation. CONCLUSION: We found 10 different mutations in this study. The correlation between genotypes and phenotypes was compatible with the reported data. Two rounds of PCR and ACRS analysis may provide important information for genetic counseling, prenatal diagnosis and management of families at risk for CAH.  相似文献   

19.
BACKGROUND: The pleomorphic adenoma is the most frequent tumor of the human lacrimal gland comprising about 50% of the epithelial tumors of this organ. Although being benign, local recurrences can occur when the first removal was incomplete and malignant transformation is also not in frequent. It is well known that many sorts of cellular oncogene products are involved in the initiation, promotion and progression of the human neoplasm. Our purpose was to know whether there is abnormal expression of P21ras in pleomorphic adenoma. METHODS: We have undertaken a study of the expression of P21ras in 5 normal tissues and 32 pleomorphic adenoma of lacrimal gland by immunohistochemical means using the monoclone antibody F-132-62 and the nuclear DNA content in the tumor was assayed by image analysis technique. RESULTS: Normal tissues of lacrimal gland were negative, 12 tumors were stained positively with the antibody. The DNA content of 14 cases of tumor was increased. Their DNA ploidy distribution pattern showed two or several peaks. Good correlation has been found between the expression of P21ras and DNA ploidy distribution pattern, the DNA ploidy distribution pattern of tumor which expressed p21ras showed mainly two or several peaks. P< 0.05. CONCLUSIONS: The result of our studies may suggest that there are increased expression of p21ras in pleomorphic adenoma and the expression of p21ras is related to the promotion and progression of pleomorphic adenoma of lacrimal gland.  相似文献   

20.
A proportion of gastric adenocarcinomas exhibit replication errors manifested as microsatellite instability. The clinicopathological and prognostic significance of this abnormality remains uncertain. This study aimed to determine the importance of microsatellite instability by analysing a large series of gastric carcinomas from an English population. Using a novel fluorescent polymerase chain reaction technique, we amplified 11 microsatellite sequences from paired normal and carcinoma DNA from 101 patients who underwent a potentially curative resection for gastric carcinoma. Overall, 21% of cases demonstrated microsatellite instability in at least one locus. At least four loci were examined in each case. A replication error positive phenotype (minimum of 29% of loci affected) was detected in 9% of cases. There was no statistically significant association between the presence of microsatellite instability or replication error positive phenotype and the patient's age, sex, tumour site, stage, node status, histological subtype or grade. Carcinomas confined to the mucosa or submucosa (T1) showed a significantly higher frequency of instability and replication error positive phenotypes than T3 lesions (P = 0.03 and P = 0.05, respectively). A larger proportion of patients who were microsatellite instability or replication error positive were alive at 5 years compared with those who were negative but this did not reach statistical significance (P = 0.15 and P = 0.16, respectively). We identified a subset of gastric carcinomas from a relatively low-risk population which showed evidence of microsatellite instability. There were no statistically significant 5-year survival advantages in cases demonstrating microsatellite instability or replication error positive phenotypes. The detection of microsatellite instability is of limited prognostic value in gastric carcinoma.  相似文献   

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