PdZn catalysts for CO2 hydrogenation to methanol using chemical vapour impregnation (CVI).

The formation of PdZn bimetallic alloys on ZnO, TiO2 and Al2O3 supports was investigated, together with the effect of alloy formation on the CO2 hydrogenation reaction. The chemical vapour impregnation (CVI) method produced PdZn nanoparticles with diameters of 3-6 nm. X-ray photoelectron spectroscopy and X-ray diffraction revealed the changes in the structure of the PdZn alloy that help stabilise formate intermediates during methanol synthesis. PdZn supported on TiO2 exhibits high methanol productivity of 1730 mmol kgcat-1 h-1 that is associated with the high dispersion of the supported PdZn alloy.

Linfangiomiomatosis con tumor retroperitoneal / Lymphangioleiomyomatosis with retroperitoneal tumor

El linfangiomioma es un tumor de presentación infrecuente, histológicamente benigno y que afecta a la mujer en edad fértil. Se reconocen una forma clínica localizada (linfangiomioma) que puede afectar a mediastino, retroperitoneo y otros órganos de forma menos habitual, y una forma difusa o politópica (linfangiomiomatosis) que casi siempre cursa con afectación del parénquima pulmonar. La localización pulmonar otorga el carácter pronóstico de la enfermedad. Histológicamente presenta canales arborescentes o ramificados de aspecto vascular rodeados de una proliferación ordenada más o menos densa de células de músculo liso sin fenómenos de atipia. Esta proliferación tiene lugar alrededor de vasos linfáticos, mediastínicos, retroperitoneales o vasos pulmonares. Presentamos un caso clínico de una mujer joven con un linfangiomioma de localización clínica inicial en retroperitoneo y posterior comprobación de su afectación pulmonar (AU)

Estudio multiinstitucional del carcinoma intraductal de mama: experiencia clinicopatológica de una serie de 121 casos / Multicenter study of intraductal breast carcinoma: clinicopathological findings in a series os 121 cases

Introducción: El interés por el estudio del carcinoma intraductal de mama ha aumentado considerablemente debido al incremento en su detección y a la introducción de diferentes opciones terapeúticas. En nuestra serie anaizamos la incidencia, las formas de presentación clínica, el estudio intraoperatorio, las características patológicas, la aplicabilidad del índice pronóstico de Van Nuys (IPVN), y las formas de tratamiento utilizadas. Material y Métodos: Estudio retrospectivo de las características clínicas y patológicas de 121 casos de carcinoma intraductal diagnosticados entre 1990 y 1997 en cinco hospitales de la provincia de Barcelona. La asociación entre las variables categóricas se contrastó mediante el test de x2. Con el modelo de regresión logística se identificaron los factores que influyeron en la práctrica de mastectomía y vaciamiento axilar. Resultados: El carcinoma intraductal representa el 5 por ciento de los cánceres de mama (9,7 por ciento en 1997). El 67 por ciento de las lesiones fueron detectadas mamográficamente. El estudio intraoperatorio se realizó en 58 casos, siendo diagnóstico de carcinoma en 43 (74 por ciento), lesión atípica en 11 (19 por ciento) y negativo en cuatro (7 por ciento). Se realizó mastectomía en el 48 por ciento y cirugía conservadores en el 52 por ciento. El estudio multivariado demuestra una mayor incidencia de mastectomía en los casos con lesión visible macroscópicamente y en tumores de mayor volumen. La práctica de estudio intraoperatorio no influyó en la opción terapeútica. El IPVN se calculó retrospectivamente: 28 por ciento score 3 o 4: 69 por ciento score 5, 6 o 7, y 3 por ciento score 8. Conclusiones: La incidencia de carcinoma intraductal ha aumentado, probablemente por la práctica extendida de la mamografía de cribado. El tratamiento quirúrgico estuvo influenciado por el tamaño del tumor y no por la práctica de estudio intraoperatorio. El IPVN retrospectivo indica un porcentaje significativo de casos score 3 o 4, que podrían ser tributarios de cirugía conservadora como único tratamiento (AU)

Proliferative activity in C-cell hyperplasia and medullary thyroid carcinoma. Evaluation by PCNA immunohistochemistry and AgNORs staining.

C cell hyperplasia (CCH) is a preneoplastic lesion that precedes the development of medullary thyroid carcinoma (MTC) in familial cases. It has been hypothesized that CCH progressively acquires the neoplastic phenotype after presenting some genetic changes that involve oncogenes and tumor suppressor genes. The proliferative activity of nodular C cell hyperplasia (NCCH) and early MTC has been assessed by PCNA (Proliferating Cell Nuclear Antigen) immunohistochemistry and nucleolar organizer regions silver staining (AgNOR) in surgical specimens of seven patients with familial MTC. The ratios of PCNA-positive nuclei in NCCH (mean 1.2, range 0.2-4) were lower than in MTC (mean 2, range 1-7%). The AgNOR scores for NCCH (mean 1.53, range 1.10-1.90) were also lower than for MTC (mean 2.10, range 1.90-2.64). The results suggest that C cells progressively acquire a higher proliferative activity in agreement with the severity of the morphologic changes in the process of hyperplasia-neoplasia that leads to widely invasive MTC.

Splenic hematoma in acute pancreatitis. Role of coagulation disorders.

Splenic hematomas are infrequent complications of acute pancreatitis. In some cases, local factors that may play a role in the pathogenesis of the hematoma (thrombosis of the splenic artery or veins, intrasplenic pseudocysts, perisplenic adhesions, enzymatic digestion) are found. In the absence of local factors, the etiology of splenic hemorrhage remains unknown. We report two cases of splenic hematoma occurring during an acute necro-hemorrhagic pancreatitis associated with renal failure that required renal replacement therapy (hemodialysis and continuous arteriovenous hemodialysis). In both cases, more than half of splenic parenchyma was affected by multiple infarctions. No local factors responsible for the splenic abnormalities were detected in either case. Thrombosis of the splenic arterial microcirculation and a coagulation disorder consistent with disseminated intravascular coagulation was detected in one patient. In the second patient, coagulation disorders secondary to either liver disease, pancreatitis and its septic complications, or extracorporeal circuit heparinization for renal replacement therapy were present. Coagulation disorders should be considered whenever a splenic hematoma is found in a patient with acute pancreatitis. Disseminated intravascular coagulation may be the etiology of a splenic hematoma in acute pancreatitis.

[Cutaneous vasculitis during bacteremia caused by Meningococcus serogroup B]. / Vasculitis cutánea en el curso de una bacteriemia por meningococo del serogrupo B.

We report a patient with an upper respiratory tract infection who presented outbreaks of erythematosus-purpuric macules and papules (the pathological substrate of which was a leukocytoclastic vasculitis with numerous intravascular thrombi) coinciding with two autolimited febrile episodes. In serial hemocultures B meningococcus was identified oral antibiotic treatment was given achieving a good clinical evolution. Although both episodes could be considered as a meningococcemia without sepsis, they could also correspond to the initial phase of a chronic meningococcemia. The possible etiopathogenesis of the cutaneous lesions is discussed and the therapeutic and prognostic repercussion of an early identification of these forms of meningococcal disease, which are poorly expressed clinically, are highlighted.

Experimental study of the efficacy of the endoluminal prosthesis in colonic anastomoses.

Colorectal surgery is still associated with a significant morbidity and mortality rate, mostly related to suture failure. We have carried out a randomized experimental study in dogs on colonic anastomoses exposed to a number of anastomotic risk situations. A total of 42 dogs was used. They were divided into three study groups (control, occlusion and diverticulitis), with and without an endoluminal tube. The aim was to assess the efficacy of the endoluminal prosthesis using clinical and radiological assessment of anastomotic healing. Pre- and post-anastomotic intraluminal pressures were also measured to determine whether these might be a factor in suture failure. There were significant differences in suture failure in animals in which the endoluminal tube was used. Mean duration of placement was 10.5 days. In the colon healing study, no significant differences were found between the groups in the pathological examination or in the assay of hydroxyproline content. The presence of the endoluminal tube may increase the maximum pressure applied on the colon wall. No significant differences were found in the intracolonic pressure differentials between the different groups or after the inclusion of the endoluminal prosthesis. The results obtained establish the efficacy of the endoluminal prosthesis in protecting the colonic anastomosis, and could be a valuable technique in colonic anastomoses with a high risk of suture dehiscence.

Atypical polypoid dermatofibroma: report of two cases.

Two cases of a hitherto undescribed special variant of dermatofibroma are reported. A man and a woman, aged 57 and 52 years, respectively, had slowly growing cutaneous tumors on the lower extremities. The tumors were exophytic and polypoid, 10 and 6 cm in maximal diameters, respectively; they were covered by rough nonulcerated skin and were joined by a short pedicle to an indurated base. Histologic examination showed some features of an otherwise conventional dermatofibroma, whereas the polypoid component was hypercellular and showed striking atypia and scattered mitotic figures. After 32 and 28 months' follow-up, the lesions did not recur after surgical excision. We suggest the term atypical polypoid dermatofibroma to summarize the special clinicopathologic features of these tumors.

Lymphoepithelial lesion in the thyroid. A non-specific histological finding.

In order to assess the specificity of lymphoepithelial lesion (LEL) in the diagnosis of thyroid lymphoma, the thyroid glands of patients with Hashimoto's disease, lymphoid infiltrates in the vicinity of papillary carcinoma, focal thyroiditis in Graves' disease and malignant lymphoma of the thyroid were studied by conventional pathological and immunohistochemical techniques using a panel of antibodies against epithelial cells (CAM 5.2) and leucocytes (LCA, pan-T, and pan-B antisera). LEL was encountered in all cases. In cases of peritumoral lymphoid infiltrates LEL represented a focal phenomenon, whereas in Hashimoto's and Graves' diseases and lymphoma, it was found in multiple areas. In cases of malignant lymphoma LEL was encountered in the vicinity of areas where diffuse parenchymal destruction by tumor cells had occurred. The results suggested that although LEL is almost always present in lymphomas it can also be encountered in other diseases of the thyroid. If therefore LEL has no diagnostic specificity, the diagnosis of malignant lymphoma must be supported by other histological findings.

Keratin expression in normal vulva, non-neoplastic epithelial disorders, vulvar intraepithelial neoplasia, and invasive squamous cell carcinoma.

The expression of AE1, AE2, AE3, and CAM 5.2 antikeratin monoclonal antibodies was investigated in 68 vulvar specimens by an avidin-biotin complex (ABC) method. They included normal vulva (NV, 10), non-neoplastic epithelial disorders (NNED, 31), vulvar intraepithelial neoplasia (VIN, 17), and squamous cell carcinoma (SCC, 10). AE1 weakly stained the basal cell layer in NV, exhibited a uniform suprabasal stain in hyperplasia, failed to stain dysplastic areas in VIN I-II, and was patchy and disorganized in VIN III and SCC. AE2 stained the upper third of the epithelium in NV, NNED, and VIN I-II, but it failed to stain VIN III basaloid and SCC; VIN III bowenoid was focally positive. AE3 offered little information, because it stained all lesions; VIN III and SCC, however, exhibited a patchy and disorganized stain. CAM 5.2 was expressed in only half of the cases of VIN III basaloid and in one case each of VIN I-II and SCC. We conclude that keratin expression varies according to the degree of dysplasia; AE1 may serve to separate certain cases of NNED from VIN I-II; AE2 and CAM 5.2 are useful to differentiate both histologic types of VIN III.

Papules in the auricular concha: lichen amyloidosus in a case of biphasic amyloidosis.

We present a patient with lichen amyloidosus on the ears and macular amyloidosis on the back. These diagnoses were supported by histological, histochemical and immunohistochemical studies. This is to the best of our knowledge the first reported case of a biphasic form of amyloidosis whose lichenoid counterpart consists of papules on the ears. This suggests that primary cutaneous localized amyloidosis may have peculiar clinical manifestations depending on the location of the lesion.

[Oat cell carcinoma of the esophagus]. / Oat cell esofágico.

Extrapulmonary locations of undifferentiated small cell carcinoma of the "oat cell" type are uncommon. In spite of its rarity, the appearance of this type of tumor has been described in various organs of the economy. Of these, the esophagus is the most common location, constituting 0.05 to 7.6% of esophageal carcinomas. Of uncertain histopathologic origin, these tumors are characterized by their extreme aggressiveness, which carries a poor short term prognosis. Surgery, radiotherapy and chemotherapy, separately or in combination, have produced discouraging results in the treatment of primitive esophageal "oat cell" carcinoma. In this paper are presented four cases of esophageal "oat cell" carcinoma treated in the Hospital de la Santa Cruz y San Pablo in 1979-1988, out of a total of 260 carcinomas in the same location. The clinical evolution and pathological findings of this type of tumor are commented. The literature on this unusual histological type of carcinoma is reviewed.

Factitial dermatosis of the breast: a possible dermatologic manifestation of Munchausen's syndrome.

We report on two cases of factitial dermatosis of the breast associated with benign fibrocystic disease. One of the patients could also be diagnosed as showing Munchausen's syndrome. The lesions were protracted and intractable, painful ulcers that recurred and eventually became bilateral, despite attempts at surgical correction. The management of factitial dermatosis of the breast is complex, and should include psychiatric referral as well as avoidance of further surgical treatment if possible.