[The clinico-pathological conference as an instrument for improving diagnostic performance ].
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Adult↗
Biomedical subjects
R Pisa
Publications and source records attributed to R Pisa.
The tetraheme cytochrome c NrfH is required to anchor the cytochrome c nitrite reductase (NrfA) in the membrane of Wolinella succinogenes.
The electron-transport chain that catalyzes nitrite respiration with formate in Wolinella succinogenes consists of formate dehydrogenase, menaquinone and the nitrite reductase complex. The latter catalyzes nitrite reduction by menaquinol and is made up of NrfA and NrfH, two c-type cytochromes. NrfA is the catalytic subunit; its crystal structure is known. NrfH belongs to the NapC/NirT family of membrane-bound c-type cytochromes and mediates electron transport between menaquinol and NrfA. It is demonstrated here by MALDI MS that four heme groups are attached to NrfH. A Delta nrfH deletion mutant of W. succinogenes was constructed by replacing the nrfH gene with a kanamycin-resistance gene cartridge. This mutant did not form the NrfA protein, probably because of a polar effect of the mutation on nrfA expression. The nrfHAIJ gene cluster was restored by integration of an nrfH-containing plasmid into the genome of the Delta nrfH mutant. The resulting strain had wild-type properties with respect to growth by nitrite respiration and nitrite reductase activity. A mutant (stopH) that contained the nrfHAIJ locus with nrfH modified by two artificial stop codons near its 5' end produced wild-type amounts of NrfA in the absence of the NrfH protein. NrfA was located exclusively in the soluble cell fraction of the stopH mutant, indicating that NrfH acts as the membrane anchor of the NrfHA complex in wild-type bacteria. The stopH mutant did not grow by nitrite respiration and did not catalyze nitrite reduction by formate, indicating that the electron transport is strictly dependent on NrfH. The NrfH protein seems to be an unusual member of the NapC/NirT family as it forms a stable complex with its redox partner protein NrfA.
Base Sequence↗
Toxic adenoma and papillary thyroid carcinoma in a patient with Graves' disease.
A case of a very rare association of toxic adenoma and papillary carcinoma with Graves' disease is presented. A 34-year-old woman developed Graves' disease with mild ophthalmopathy. An ultrasound revealed diffuse thyroid enlargement with a hypoechoic pattern and a hypoechoic nodule with regular edges of 1.6 cm in diameter at the lower pole of the left lobe. A thyroid 131I scintiscan showed a diffuse and homogeneous 131I distribution. The 131I uptake (RAIU) was elevated. One year later, while still on a low dose of methimazole, the patient had a recurrence of hyperthyroidism following an iodine load from a contrast agent. A further thyroid ultrasound confirmed the previously described pattern but showed a new hypoechoic nodule of 1.1 cm with irregular edges in the left lobe. A thyroid 131I scintiscan this time demonstrated a hyperactive area localised in the larger nodule and a lower diffuse uptake of the remaining tissue. Because of the worsening of the symptoms of hyperthyroidism, the patient had a left lobectomy. On histological examination, the larger nodule was well encapsulated and showed the characteristics of a hyperfunctioning follicular adenoma. The smaller nodule was a typically unencapsulated papillary carcinoma. Several other microfoci of papillary carcinoma were also found in the adjacent tissue. Completion of thyroidectomy was therefore performed, followed by 131I ablative therapy and thyroxine suppressive treatment. This observation suggests that the chronic abnormal stimulation of the thyroid gland by the thyroid-stimulating antibody (TSAb) may facilitate the neoplastic transformation of the thyrocytes in individuals with a critical genetic background.
Adenoma↗
The single cysteine residue of the Sud protein is required for its function as a polysulfide-sulfur transferase in Wolinella succinogenes.
The periplasmic Sud protein which is induced in Wolinella succinogenes growing by polysulfide respiration, has been previously proposed to serve as a polysulfide binding protein and to transfer polysulfide-sulfur to the active site of polysulfide reductase [Klimmek, O, Kreis, V., Klein, C., Simon, J., Wittershagen, A. & Kröger, A. (1998) Eur. J. Biochem. 253, 263-269.]. The results presented in this communication suggest that polysulfide-sulfur is covalently bound to the single cysteine residue (Cys109) of the Sud monomer, and that Cys109 is required for tight binding of polysulfide-sulfur and for sulfur transfer. A modified Sud protein [(C109S)Sud-His6] in which the cysteine residue was replaced by serine, did not catalyze sulfur transfer from polysulfide to cyanide and did not stimulate electron transport to polysulfide, in contrast to Sud-His6. The polysulfide-sulfur bound to (C109S)Sud-His6 was fully removed upon dialysis against sulfide. After this treatment, Sud-His6 retained one sulfur atom per monomer; thiocyanate was formed upon addition of cyanide to the preparation. After incubation of Sud-His6 with polysulfide, a proportion of the Sud-His6 monomers carried one or two sulfur atoms, as shown by matrix-assisted laser desorption ionization mass spectrometry. The sulfur atoms were absent from monomers derived from Sud-His6 treated with cyanide and from (C109S)Sud-His6 incubated with polysulfide.
Amino Acid Substitution↗
Recurrent postinfantile syncytial giant cell hepatitis after orthotopic liver transplantation.
Syncytial giant cell hepatitis is a severe form of hepatitis characterized by diffuse giant cell transformation of hepatocytes. The disease may evolve to chronic cholestatic cirrhosis necessitating liver transplantation. We report the case of an adult liver transplant recipient presenting with early recurrent disease without concomitant clinicobiochemical syndrome. Early recurrence of giant cell hepatitis after liver transplantation favors the hypothesis of a transmissible agent as the etiology of the disease. Routine follow-up liver biopsy is necessary in these cases in order to gain more information about the precise incidence and aggressivity of disease recurrence in the allograft.
Adolescent↗
High-dose cyclophosphamide, etoposide and BCNU (CVB) with autologous stem cell rescue in malignant lymphomas.
Eighteen patients with malignant lymphoma, 10 non-Hodgkin's and 8 Hodgkin's, were treated with high-dose CVB (cyclophosphamide 4 x 1.5 g/m2, etoposide 4 x 250-400 mg/m2, carmustine 4 x 150-200 mg/m2), followed by autologous peripheral blood stem cells (PBSC, 13 patients) or bone marrow (BM, 5 patients) transplantation. At the time of autograft 6 patients were in complete remission (CR), 3 in partial remission (PR) and 5 in relapse (4 sensitive, 1 resistant), whereas 4 had progressive disease. All CR patients had poor prognostic features at presentation. PBSC were collected at the time of rapid hematologic recovery after intense chemotherapy by means of a cell separator. All patients engrafted. Median time to achieve > or = 0.5 x 10(9)/l polymorphonuclear cells (PMN) and > or = 50 x 10(9)/l platelets was 13 days for both cell types in PBSC autografted patients, versus 20 and 28 days respectively in BM autografted patients. A significant advantage of PBSC over BM was found in terms of time needed to recover either PMN > or = 0.5 and PMN > or = 1 x 10(9)/l (p = 0.01). Autograft-related toxicity consisted mainly of moderate severity interstitial pneumopathy (3 patients), and veno-occlusive disease (1 patient) that resolved completely. Of the 12 patients autografted with detectable disease, 6 (50%) obtained a CR. Seven out of 18 autografted patients (39%) had disease progression within 1 to 5 months of autograft. The projected progression-free survival is over 50% at 4 years and it was significantly longer in patients with sensitive disease than in those with resistant disease (p = 0.01). The efficacy and the low toxicity of CVB suggest that autograft with PBSC may be proposed for the primary treatment of poor prognosis malignant lymphomas.
Adult↗
Alpha interferon treatment of chronic hepatitis C in beta-thalassaemia.
In this open, pilot study, interferon (IFN) alpha-2b seemed effective in the treatment of hepatitis C virus (HCV) infection in patients with beta-thalassaemia. In seven of nine patients who completed the study alanine aminotransferase activities returned to normal, and a completely stable response 24 months after treatment was seen in five. Liver biopsy specimen showed a clear reduction in portal, periportal, and lobular necroinflammation in all five cases. Three patients stopped treatment early because of side effects.
Adolescent↗
Expression of leukocyte adhesion molecules in the liver of patients with chronic hepatitis B virus infection.
Virus-specific T-cell responses are believed to be involved in the pathogenesis of liver cell injury secondary to hepatitis B virus infection. In this study, liver biopsy specimens from patients with chronic hepatitis B virus infection were analyzed for expression of two major pathways of adhesion used by cytotoxic T cells to interact with target cells. The lymphocyte function-associated antigen 3 was found preferentially expressed on hepatocytes of patients with active hepatitis B virus replication, whereas the expression of the intercellular adhesion molecule 1 on hepatocytes seemed more closely related with inflammatory activity. Adhesion molecules were also highly expressed on T lymphocytes found in areas of piecemeal and spotty necrosis, indicating the presence of antigen-specific "memory" T cells at the site of hepatocellular injury. This study suggests that the expression of the lymphocyte function-associated antigen 3 on hepatocytes may be important for viral elimination. The coordinate expression of the intercellular adhesion molecule 1 may regulate inflammatory response and enhance viral antigen presentation to T cells. Conversely, the absence of hepatocyte adhesion molecules might be a favorable factor for viral persistence.
Antigens, Surface↗
Natural history of congestive gastropathy in cirrhosis. The Liver Study Group of V. Cervello Hospital.
In a prospective study of the natural history of congestive gastropathy, 212 consecutive cirrhotic patients (75 treated with sclerotherapy) were included. Mean follow-up was 46 months. Mild gastropathy (mosaiclike pattern) was found in 110 patients and severe gastropathy (granular mucosa with cherry spots) was found in 20. Prevalence of Helicobacter pylori, formerly Campylobacter pylori, was 50% in patients without, 43% in those with mild, and 28% in those with severe gastropathy. Congestive gastropathy was significantly more frequent in patients treated with sclerotherapy (83% vs. 50%, P less than 10(-5)). Sixty-month actuarial proportions of patients free of anemia (in the absence of hematemesis or melena), were 17% with severe, 62% with mild, and 93% without gastropathy (P less than 10(-8]. Corresponding figures for overt bleeding were 25%, 73%, and 87% (P less than 10(-7], whereas those for survival were 46%, 72%, and 85% (P = 0.0005), respectively. A multivariate regression analysis supported the following conclusions: (a) sclerotherapy and the presence of large esophageal varices significantly increase the risk of congestive gastropathy, which (b) is a significant risk indicator of both chronic and overt bleeding but does not independently affect survival.
Adult↗
[Malignant epithelioid hemangioendothelioma of the liver. Description of a case].
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Biopsy↗
Procollagen type I production by hepatocytes: a marker of progressive liver disease?
The presence of collagen-producing cells and its relation to disease activity were determined in cryostat liver tissue sections from subjects with active cirrhosis (n = 15), inactive cirrhosis (n = 5), chronic persistent hepatitis (n = 8), or normal histology (n = 3) by means of an immunofluorescence technique using a monoclonal antibody to the carboxy-terminal domain of procollagen type I (anti-Pc). In all patients with active cirrhosis hepatocytes showed a strong intracellular staining with anti-Pc; in 4 of them bileducts also showed a membrane-like reaction. By contrast, tissue sections from chronic inactive liver disease and normal liver were essentially negative. These findings suggest that in chronic liver disease hepatocytes and sometimes biliary epithelium produce collagen and that production is related to disease activity. The detection of active production of procollagen type I by hepatocytes could become a useful marker of progressive liver disease.
Adult↗
Phenoxy herbicides and soft-tissue sarcomas in female rice weeders. A population-based case-referent study.
A population-based case-referent study was conducted in an area of northern Italy where rice growing is the predominant agricultural activity and phenoxy herbicides have been used since 1950. Manual rice weeding was formerly performed by a seasonal female working population; in the early 1950s these women were concurrently exposed to chemical herbicides. Sixty-eight persons representing incident and histologically revised cases (31 women) and 158 population referents (73 women) were interviewed. The cases were histologically confirmed independently by two blinded pathologists, and exposure to phenoxy herbicides was assessed by two blinded pesticide researchers. An age-adjusted odds ratio of 0.91 was found for the living men (with suspect exposures; no man diagnosed as a case had been exposed with certainty to phenoxy herbicides). Among the living women the relative risk was 2.7 (90% confidence interval 0.59-12.37), and it further increased when attention was restricted to women exposed in the whole 1950-1955 period and to younger age groups.
2,4,5-Trichlorophenoxyacetic Acid↗
On the causal association between exposure to leather dust and nasal cancer: further evidence from a case-control study.
A case-control study was performed on the incident cases of nasal cavity tumours which occurred between 1968 and 1982 among the residents of Vigevano (Lombardy region, northern Italy). This area is characterised by a high prevalence of shoemakers (especially in leather); the activity has predominated in Vigevano since the beginning of this century. Twenty one cases were identified (16 men and five women); 20 were histologically confirmed as nasal epithelial tumours; 17 had already died at the time of interview and the occupational history was obtained from the next of kin. Two controls per case were selected from the general population and matched by vital status, age, sex, and residence. The overall odds ratio for the subjects exposed to leather dust was 47.1 for men and 3.5 for women. The odds ratio was higher for adenocarcinoma and among the workers exposed to the worst working conditions. A significant trend for the level of exposure to leather dust was found. Nevertheless, even the jobs characterised by a relatively low exposure were found to have a significantly higher risk (OR = 7.5). Smoking habits and exposure to solvents are unlikely to confound the relation between exposure to leather and nasal tumours.
Adenocarcinoma↗
Pheochromocytoma of the urinary bladder.
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Adult↗
A distinctive cutaneous malignant neoplasm expressing the Langerhans cell phenotype. Synchronous occurrence with B-chronic lymphocytic leukemia.
The authors describe a 63-year-old woman who developed a histologically distinctive malignant cutaneous neoplasm composed of large pleomorphic cells with abundant cytoplasm and multilobate, often clefted nuclei that occasionally contained small nucleoli. This neoplastic cell population metastasized to a regional lymph node already involved by a B-cell derived chronic lymphocytic leukemia expressing surface IgMk, BA-1, and OKT1. The large metastatic tumor cells lacked surface immunoglobulin, B-lymphocyte associated antigen BA-1, T-lymphocyte associated antigens OKT1 and OKT3, and the monocyte/macrophage markers lysozyme and alpha 1-antichymotrypsin. These tumor cells expressed HLA-DR antigens, adenosine triphosphatase (ATPase), OKT6, and contained S-100 protein, i.e., they expressed the phenotype peculiar to epidermal Langerhans cells. The typical clinical and histologic features of Histiocytosis X were absent. Thus, this case appears to represent a distinctive cutaneous neoplasm composed entirely of malignant cells of dendritic cell origin which, by immunophenotypic and histochemical analysis, appear to be related to epidermal Langerhans cells.
Antibodies, Monoclonal↗
Synovial sarcoma: with radial nerve involvement.
An unusual case of radial nerve involvement at the elbow by a synovial sarcoma is reported. The patient was a 16-year-old Caucasian girl presenting with signs of a radial nerve palsy. Treatment was by surgical excision of the tumour and grafting the defect in the radial nerve. The histological diagnosis was a synovial sarcoma. Recovery of function was almost complete eight months later.
Adolescent↗
Epithelioid sarcoma: a tumor of myofibroblasts, or not?
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Fibroblasts↗
[Benign epithelial neoplasms of Vater's ampulla. Usefulness of the "epithelial dysplasia" concept in prognosis and surgical strategy].
The surgical behaviour in front of the benign epithelial tumors (adenomas) of Vater's ampulla is object of discrepancies due to the possible malignant evolution of such neoplasms. The authors stress the basic importance of a careful examination of histological bioptic material before and/or during operation, which, through the identification of the degree of epithelial dysplasia, may lead to the choice of the tecnique to be adopted. In 2 of the 3 cases reported by the authors, showing a low degree dysplasia of the papillary tumor, a submucous papillectomy was performed; in the third case, where histology showed severe dysplasia and some other elements of risk were present (patient's age and macroscopic features of the tumors), the surgeons performed a duodenopancreatectomy. Semiseriated histological sections of the surgical specimen revealed the presence of carcinomatous areas. The authors think simple papillectomy to be the surgical procedure to follow when low grade dysplasia of ampulla is documented, and duodenopancreatectomy to be performed in high risk conditions as high grade dysplasia and macroscopic features suggestive of malignancy. In addition, the authors deal with epidemiology, clinics and instrumental diagnostics of such benign neoplasms of ampulla, on the basis of their own experience and the review of the few cases reported in literature.
Adenoma↗