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Biomedical subjects

A Pimenta

Publications and source records attributed to A Pimenta.

At least 19 recordsLinked to original sources
PubMed2006

Marginal zone lymphoma of both spleen and kidney displaying transformation into large B-cell lymphoma.

We report a case of simultaneous involvement of the spleen and the left kidney in a marginal zone lymphoma with a monotypic lymphoplasmacytic cell component, which transformed into a diffuse large B-cell lymphoma of the immunoblastic type. PCR showed that the small and large B-cell populations carried the same type of immunoglobulin heavy chain gene rearrangement. This type of rearrangement was detected in the spleen, the latero-aortic lymphadenopathy and the kidney demonstrating that it is the same lymphoma that affected both organs and the lymph nodes. Primary renal lymphoma is very rare and only a few cases of renal marginal zone lymphoma, MALT type, have been reported. Involvement of simultaneous multiple sites has been described in MALT type lymphoma, but splenic involvement secondary to renal MALT lymphoma seems to have never been observed. Nevertheless, in our case the huge size of the spleen associated with splenic hilar node involvement is consistent with primary splenic marginal zone lymphoma. The extension into latero-aortic lymph nodes of this lymphoma can explain secondary kidney involvement. The nodal Kaposi's sarcoma observed in this patient of Mediterranean origin was probably coincidental.

Aged↗
PubMed2004

MUC5B expression in gastric carcinoma: relationship with clinico-pathological parameters and with expression of mucins MUC1, MUC2, MUC5AC and MUC6.

Previous studies have shown that mucin expression can be used to evaluate differentiation patterns of gastric carcinoma: MUC5AC expression is associated with diffuse type and early gastric carcinomas, and MUC2 expression is associated with mucinous gastric carcinomas. The role played by MUC5B in the evaluation of differentiation and biological behaviour of gastric carcinoma is largely unknown. Our aim was to characterise the pattern of expression of mucins MUC1, MUC2, MUC5AC, MUC5B and MUC6 in a series of 50 gastric carcinomas to evaluate whether MUC5B expression was associated with the clinico-pathological characteristics of the cases and/or with the co-expression of other mucins. A panel of six monoclonal antibodies (HMFG1, SM3, PMH1, CLH2, EU-MUC5Ba and CLH5) was used to determine the expression of mucins (MUC1, MUC1 underglycosylated form, MUC2, MUC5B, MUC5AC and MUC6, respectively) using immunohistochemistry. Cases were considered positive if more than 5% of the cells expressed immunoreactivity for the several mucins evaluated. Our results showed that: (a) expression of MUC5B was observed in 11 cases (22.0%) and was associated with the "unclassified" histological type of gastric carcinoma according to Laurén ( P = 0.03) and with the absence of venous invasion ( P = 0.02); (b) in this series, MUC5B expression had no impact on survival of patients with gastric carcinoma; (c) the expression of MUC5B was associated with the co-expression of MUC5AC ( P = 0.02) and (d) none of the cases with the so-called complete intestinal phenotype of mucin expression expressed MUC5B.

Antibodies, Monoclonal↗
PubMed2004

Clinicopathological significance and survival influence of p53 protein expression in gastric carcinoma.

AIMS: Mutations in the gene coding for p53 protein are among the most frequent genetic alterations observed in human cancers. The relevance and biological significance of p53 expression in gastric carcinoma are far from being fully established. The aim of our study was to evaluate the influence of p53 detected by immunohistochemistry in the clinicopathological behaviour of a series of gastric carcinoma cases. METHODS AND RESULTS: Samples from 163 patients treated by gastric resection for gastric carcinoma between 1988 and 1995 were used. Surgical specimens were evaluated for the presence of p53 protein detected by immunohistochemistry with a monoclonal antibody. Cases were classified as positive or negative for p53. Several clinicopathological parameters and c-erb B-2 expression were analysed in the same series and compared with the expression of p53. Cumulative survival was evaluated using univariate analysis and Cox model regression. p53 expression was identified in 41 carcinomas (25.2%) and was significantly associated with venous invasion (P = 0.049), lymph node metastases (P = 0.01) and c-erb B-2 expression (P = 0.003). All the parameters except gender, tumour size and Laurén's classification influenced survival on univariate analysis. p53 expression correlated with overall survival (P = 0.006) and survival in the subgroup of patients with intestinal type carcinoma (P = 0.04). In the subgroup of patients with carcinomas not expressing c-erb B-2, p53 expression significantly influenced cumulative survival (P = 0.02). CONCLUSIONS: p53 expression is associated with the aggressive biological behaviour of gastric carcinomas and is related to cumulative survival.

Adult↗
PubMed2004

In vivo expression of the mannose-resistant fimbriae of Photorhabdus temperata K122 during insect infection.

Photorhabdus temperata K122 is an entomopathogenic bacterium symbiotically associated with nematodes of the family Heterorhabditidae: Surface fimbriae are important for the colonization of many pathogenic bacteria, and here we report the nucleotide sequence and analysis of the expression of a 12-kbp fragment encoding the mannose-resistant fimbriae of P. temperata (mrf). The mrf gene cluster contains 11 genes with an organization similar to that of the mrp locus from Proteus mirabilis. mrfI (encoding a putative recombinase) and mrfA (encoding pilin), the first gene in an apparent operon of nine other genes, are expressed from divergent promoters. The mrfI-mrfA intergenic region contains inverted repeats flanking the mrfA promoter. This region was shown to be capable of inversion, consistent with an ON/OFF regulation of the operon. In in vitro liquid cultures, both orientations were detected. Nevertheless, when we analyzed the expression of all of the genes in the mrf locus by semiquantitative reverse transcription-PCR during infection of Galleria mellonella (greater wax moth) larvae, expression of mrfA was not detected until 25 h postinfection, preceding the death of the larvae at 32 h. In contrast, mrfJ (a putative inhibitor of flagellar synthesis) was expressed throughout infection. Expression of mrfI was also detected only late in infection (25 to 30 h), indicating a possible increase in inversion frequency at this stage. In both in vitro liquid cultures and in vivo larval infections, the distal genes of the operon were expressed at substantially lower levels than mrfA. These results indicate the complex regulation of the mrf cluster during infection.

Animals↗
PubMed2003

[Leiomyoma of the bladder. Analysis of a collection of 90 cases].

INTRODUCTION: Bladder leiomyomas (BL) are rare. Most publications regarding these tumours are reports of isolated cases; therefore they don't allow an evaluation of diagnostic and treatment procedures. MATERIAL & METHODS: We preformed a pooled analysis of 90 cases of BL reported in the literature. RESULTS: Mean age was 45.3 (19 to 85 years), 68 (75.6%) were women. Filling symptoms were the most frequently reported (50%), followed by voiding symptoms (24.4%). Twenty four patients (26.7%) were asymptomatic. Tumours were endoluminal in 46 patients (51.1%), intramural in 27 (30%) and extravesical in 15 (16.7%). A laparotomy was performed in 56 patients (62.2%), with enucleation in 29 (32.2%), partial cystectomy in 25 (27.8%) and total cystectomy in 2 (2.2%). A transurethral resection was preformed in 27 (30%) and a transvaginal resection in 5 (5.6%). Two patients underwent conservative treatment. In 3 cases there were reports of recurrence and one patient got a vesicovaginal fistula. CONCLUSIONS: Although BL are rare, when evaluating bladder tumours, imaging techniques can make suspect of this neoplasm. Surgical treatment of these tumours has a very high success rate. Usually an enucleation or a transurethral resection is sufficient to render the patient tumour free, avoiding a more iatrogenic surgery.

Adult↗
PubMed2001

Neurofilaments consist of distinct populations that can be distinguished by C-terminal phosphorylation, bundling, and axonal transport rate in growing axonal neurites.

We examined the steady-state distribution and axonal transport of neurofilament (NF) subunits within growing axonal neurites of NB2a/d1 cells. Ultrastructural analyses demonstrated a longitudinally oriented "bundle" of closely apposed NFs that was surrounded by more widely spaced individual NFs. NF bundles were recovered during fractionation and could be isolated from individual NFs by sedimentation through sucrose. Immunoreactivity toward the restrictive C-terminal phospho-dependent antibody RT97 was significantly more prominent on bundled than on individual NFs. Microinjected biotinylated NF subunits, GFP-tagged NF subunits expressed after transfection, and radiolabeled endogenous subunits all associated with individual NFs before they associated with bundled NFs. Biotinylated and GFP-tagged NF subunits did not accumulate uniformly along bundled NFs; they initially appeared within the proximal portion of the NF bundle and only subsequently were observed along the entire length of bundled NFs. These findings demonstrate that axonal NFs are not homogeneous but, rather, consist of distinct populations. One of these is characterized by less extensive C-terminal phosphorylation and a relative lack of NF-NF interactions. The other is characterized by more extensive C-terminal NF phosphorylation and increased NF-NF interactions and either undergoes markedly slower axonal transport or does not transport and undergoes turnover via subunit and/or filament exchange with individual NFs. Inhibition of phosphatase activities increased NF-NF interactions within living cells. These findings collectively suggest that C-terminal phosphorylation and NF-NF interactions are responsible for slowing NF axonal transport.

Amoxicillin-Potassium Clavulanate Combination↗
PubMed2001

[Renal neoplasm with vena cava involvement].

Renal cancer with vena cava tumour thrombus is relatively rare (4 to 10%). Because of the poor results obtained with any kind of alternative therapy (e.g. radiation, hormonal, chemotherapy and immunotherapy) operation with complete removal of the vena cava tumour thrombus continues to be the better method of treatment. The prognostic significance of the cephalic extent of an inferior vena caval tumor thrombus associated with renal cell carcinoma is controversial. Long-term survival after surgical treatment is possible in patients with localized renal cell carcinoma (survival 50% at five years). The authors report a case of vena caval extension of renal cell carcinoma in a 70-years-old man. The patient presented with a history of right lumbar pain and pedal edema. Magnetic Resonance demonstrated the presence and the level of tumoral thrombus. The patient was submitted to a radical nephrectomy and complete removal of tumor thrombus from vena caval.

Aged↗
PubMed2001

Clinicopathologic profiles and prognosis of gastric carcinomas from the cardia, fundus/body and antrum.

BACKGROUND/AIMS: The putative influence of tumor location on the biologic behavior of gastric carcinomas remains controversial. The aim of this study was to investigate if carcinomas arising in the three types of gastric mucosa (cardia, fundus/body and antrum) have different clinical and pathologic profiles and carry a different prognosis. METHODS: Three hundred and two patients with cardia or gastric carcinoma resected between 1984 and 1996 were retrospectively studied. Cases were divided in three groups according to tumor location: cardia (n = 80); fundus/body (n = 60); antrum (n = 162). The three groups were crosstabulated with clinic and pathologic parameters, such as age, sex, macroscopy, histology, desmoplasia, tumor size, depth of tumor wall penetration, nodal status, venous invasion and stage. Survival rates were calculated for the three locations according to the aforementioned parameters. Univariate survival analysis and Cox regression were performed for each location. RESULTS: Cases from the cardia and fundus/body were similar and distinct from antrum cases according to macroscopy, tumor size, depth of wall penetration, venous invasion, nodal status and stage. Cases from fundus/body were similar to antrum cases and distinct from cardia cases according to gender and Laurén's classification. An overall difference in survival between the three locations was observed (p = 0.006). Cumulative survival was better for patients with carcinomas in the antrum than in the cardia (p = 0.04) and in the fundus/body (p = 0.003); no significant differences were observed in survival between cardia and fundus/body carcinoma cases. Cox regression identified stage and venous invasion as prognostic factors for patients with carcinomas in the three locations. In the group of cardia tumors, older patients had a worse outcome and in the group of fundus/body carcinomas, large tumors were associated with a poorer survival. CONCLUSIONS: Our results show that cardia carcinoma and antrum carcinoma are distinct gastric carcinoma entities whereas fundus/body carcinoma shares some characteristics from both entities.

Adult↗
PubMed2001

[Arterial blood pressure behavior during the administration of intravenous streptokinase, in patients with acute myocardial infarction].

OBJECTIVE: To evaluate the effect on blood pressure (BP) of intravenous (i.v.) streptokinase (SK) in patients (PTS) with acute myocardial infarction (AMI). DESIGN: Retrospective study with analysis of BP registers ten minutes before and during SK infusion. SETTING: PTS admitted to the Coronary Care Unit (CCU) of Santo António Hospital, Oporto. PATIENTS: Thirty-eight male PTS, average ages of 54, ranging from 38 to 67, AMI confirmed, and criteria to thrombolytic therapy. One patient was excluded on account of persistent hypotension since admission. MATERIAL AND METHODS: I.v. infusion of 1.500.000 U of SK over 60 minutes, preceded by 200 mg i.v. of prednisolone. BP and heart rate (HR) were evaluated with Datascope Accutorr 1A set. The lowest value of the systolic BP (SBP) recorded ten minutes before SK infusion was considered the baseline value. We valued the reduction of SBP above 15%, defining its fall as the difference between the baseline value and the minimum value of SBP recorded during the infusion. Hypertension was defined to SBP values below 90 mmHg. MAIN RESULTS: The fall was 40.4 +/- 22.1 mmHg (range 9 to 102, having been recorded the minimum value at 22.9 +/- 10.9 minutes. It was accompanied by diastolic BP (DBP) fall of 30.6 +/- 18.9 mmHg (range -2 to 76) and by a HR increasing from 76.2 +/- 13.7 beats/min. to 80.8 +/- 14.1 beats/min. (p < 0.01). In 86% of the PTS this fall was transient, lasting 8.9 +/- 6.3 minutes, and was corrected by slowing or stopping the infusion for a few minutes and placing the patient in Trendelenburg position. Two PTS needed sympaticomimetic amines because of persistent BP reduction despite the previous measures. 92% of the PTS had a SBP fall higher than 15% in relation to the baseline value. The SBP was kept over 90 mmHg in 20 PTS (54%); hypotension was recorded in the remaining 14 PTS (38%), and in 10 (27%) of these the SBP fell below 80 mmHg. We couldn't prove that the infarction and the extension of the ischemic lesion had influenced this BP fall. CONCLUSIONS: The BP reduction during treatment with high doses of SK deserves some attention because, although transient and easily reversible, it is frequent and sometimes significative. It demands then careful monitoring in order to avoid the hypoperfusion to the ischemic myocardium, that could jeopardize the potential benefits of reperfusion in the reduction of infarction area, the main objective of the thrombolytic treatment.

Adult↗
PubMed1999

Kinesin-mediated transport of neurofilament protein oligomers in growing axons.

We examined cytoskeleton-associated forms of NF proteins during axonal neuritogenesis in cultured dorsal root ganglion (DRG) neurons and NB2a/d1 neuroblastoma. In addition to filamentous immunoreactivity, we observed punctate NF immunoreactivity throughout perikarya and neurites. Immuno-electron microscopy revealed this punctate immunoreactivity to consist of non-membrane-bound 75 nm round/ovoid structures consisting of amorphous, fibrous material. Endogenous and microinjected NF subunits incorporated into dots prior to their accumulation within filaments. A transfected GFP-conjugated NF-M incorporated into dots and translocated at a rate consistent with slow axonal transport in real-time video analyses. Some dots converted into a filamentous form or exuded filamentous material during transport. Dots contained conventional kinesin immunoreactivity, associated with microtubules, and their transport into axons was blocked by anti-kinesin antibodies and nocodazole. These oligomeric structures apparently represent one form in which NF subunits are transported in growing axons and may utilize kinesin as a transport motor.

Animals↗
PubMed1998

Membrane-associated molecules guide limbic and nonlimbic thalamocortical projections.

Membrane-associated signals expressed in restricted domains of the developing cerebral cortex may mediate axon target recognition during the establishment of thalamocortical projections, which form in a highly precise manner during development. To test this hypothesis, we first analyzed the outgrowth of thalamic explants from limbic and nonlimbic nuclei on membrane substrates prepared from limbic cortex and neocortex. The results show that different thalamic fiber populations are able to discriminate between membrane substrates prepared from target and nontarget cortical regions. A candidate molecule that could mediate selective choice in the thalamocortical system is the limbic system-associated membrane protein (LAMP), which is an early marker of cortical and subcortical limbic regions (Pimenta et al.,1995) that can promote outgrowth of limbic axons. Limbic thalamic and cortical axons showed preferences for recombinant LAMP (rLAMP) in a stripe assay. Incubation of cortical membranes with an antibody against LAMP prevented the ability of limbic thalamic fibers to distinguish between membranes from limbic cortex and neocortex. Strikingly, nonlimbic thalamic fibers also responded to LAMP, but in contrast to limbic thalamic fibers, rLAMP inhibited branch formation and acted as a repulsive axonal guidance signal for nonlimbic thalamic axons. The present studies indicate that LAMP fulfills a role as a selective guidance cue in the developing thalamocortical system.

Animals↗
PubMed1998

[Left ventricular pseudoaneurysm: a rare complication of acute myocardial infarction diagnosed by echocardiography].

Postmyocardial infarction left ventricular pseudoaneurysm resulting from free wall rupture is a very rare finding. Its recognition during life is even rarer. Definitive preoperative diagnosis is difficult, implying, in a great number of cases, the use of multiple imaging modalities. A case of a left ventricular pseudoaneurysm as a mechanical complication of acute myocardial infarction, which was diagnosed by transthoracic echocardiography, is reported. The authors emphasize its rarity, the diagnostic difficulties involved and the contribution of echocardiography to the characterization of that lesion, allowing a definitive diagnosis prior surgery in this case.

Aged↗
PubMed1997

Limbic system-associated membrane protein (LAMP) induces neurite outgrowth and intracellular Ca2+ increase in primary fetal neurons.

The ability of cell adhesion molecules (CAMs) to transduce cell surface signals into intracellular responses is critical for developing neurons, particularly during axonal pathfinding and targeting. It has been suggested that different CAMs can promote neuronal outgrowth via activation of common neuronal CAM-specific second-messenger pathways, although the elements involved in this cascade could differ. Limbic system-associated membrane protein (LAMP), a member of the Ig superfamily, is a molecule that promotes cell adhesion and neurite outgrowth from specific populations of fetal neurons. In the present study, we show that LAMP can induce several types of calcium (Ca2+) signals. Neurite outgrowth is promoted if fetal hippocampal neurons are grown on lamp-transfected CHO cells. This LAMP-induced outgrowth of neurons is mediated in part through activation of L-type Ca channels. Application of soluble LAMP to cultures of fetal hippocampal neurons caused a sustained (up to 60 min) elevation of intracellular Ca2+ as measured by fluo-3 fluorescence on a confocal microscope. The number of responding hippocampal neurons was initially low, but increased with age in culture and the [Ca2+]i elevation was only partially decreased by an L-type Ca(2+)-channel blocker. In contrast, at all times in culture, only a small fraction of neurons from visual cortex responded to LAMP application and only with transient elevation of cytosolic Ca2+ (< 15 min). Based on these observations, LAMP appears to function primarily through homophilic interactions and acts in part by modulating intracellular Ca2+ levels during neurite outgrowth by increasing the Ca2+ influx through L-type calcium channels, but has additional effects on intracellular Ca2+ signaling at later developmental stages.

Animals↗
PubMed1997

[The echocardiographic diagnosis of a rare complication of an aneurysm of the sinus of Valsalva].

We report the case of a patient with complete heart block caused by extension of a congenital aneurysm of the sinus of Valsalva into the upper interventricular septum, which was diagnosed by transthoracic and transesophageal echocardiography. We emphasize the rarity of this pathology and the value of transesophageal echocardiography in its assessment, providing a complete anatomicofunctional characterization and allowing surgical repair without previous cardiac catheterization.

Adult↗
PubMed1997

[Vesico-scrotal hernia. Report of a clinical case].

Incidental discovery of vesical hernias during herniorrhaphy is quite common. In such cases, patients are usually asymptomatic since the hernia portion is small and easily repairable. On the other hand, vesical solid protrusion to the scrotum is quite unusual, and is generally found associated to obstructive urinary symptoms. Management involves basically the correction of any associated obstructive conditions, correction of the vesical hernia and herniorrhaphy.

Genital Diseases, Male↗
PubMed1996

Granular cell tumour and leiomyomatosis of the esophagus--a non-coincidental association?

One case of esophageal granular cell tumour (GCT) associated with diffuse leiomyomatosis of the distal esophagus is presented. The rarity of each of the lesions per se raises the possibility that the association between GCT and diffuse leiomyomatosis, a previously unreported finding, is not coincidental. In view of the present knowledge on both conditions we suggest that an underlying genetic alteration may be responsible for the hereby described association.

Esophageal Neoplasms↗