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J C de Almeida

Publications and source records attributed to J C de Almeida.

At least 19 recordsLinked to original sources
PubMed2002

The control of BhB10-1 gene expression in the salivary gland of Bradysia hygida (Diptera, Sciaridae) is disrupted in vivo by a delayed effect of cycloheximide.

BhB10-1 is an amplified gene present in DNA puff B10. This gene is very active in the salivary gland regions S1 and S3 at the end of the larval development. Two transcripts of this gene, 1.3 and 1.1 kb in size, were detected. A secretory protein, SP23, is the product of BhB10-1. In this work, we present evidence supporting the hypothesis that a biphasic process of mRNA degradation is an important component in the control of BhB10-1 gene expression. The 1.3 kb transcript, by a process of poly(A) tail shortening, is converted to the inactive transcript of 1.1 kb which is detected during and after the period of SP23 expression. Cycloheximide in very low concentration, if applied at a proper time, can disrupt this process leading to extended periods of 1.3 kb RNA detection and SP23 synthesis. A tentative model is proposed to explain this phenomenon.

Animals↗
PubMed2000

A dual role of 20-hydroxyecdysone in the control of protein synthesis related to DNA puff activity in the anterior region of Bradysia hygida (Diptera, Sciaridae) salivary gland.

During the last 30 h of the larval stage, the salivary glands of Bradysia hygida show the amplification of some genes, resulting in the formation of two successive groups of DNA puffs, which direct the synthesis of two different sets of polypeptides. Incubation of anterior (S1) salivary gland regions, at age E7, beginning of first group of DNA puffs activity, in culture medium for 2 to 10 h results in a decrease in the synthesis of the polypeptides characteristic of this period. However, during subsequent incubation (from E7 to E7+12 h-24 h), when the second group of DNA puffs is active, S1 regions were able to synthesize some polypeptides characteristic of this period. The role of 20-OH ecdysone was studied, in vitro and in vivo, during these two periods of protein synthesis in S1 regions. The presence of the hormone was shown to be necessary to maintain, in vitro, the synthesis of the first set of polypeptides and was strongly inhibitory, in vitro and in vivo, to the synthesis of the second set of polypeptides. Thus, it is likely that the activity of the two distinct groups of DNA puffs is under opposite 20-OH-ecdysone control mechanisms.

Animals↗
PubMed1999

The DNA puff BhB10-1 gene encodes a glycine-rich protein secreted by the late stage larval salivary glands of Bradysia hygida.

We present the molecular characterization of a gene of Bradysia hygida DNA puff B10 whose temporal expression in the salivary gland correlates with the puff expansion. The transcription unit of this gene, named BhB10-1, was mapped in a 2-kb EcoRI genomic fragment that is amplified in the salivary gland of late fourth instar larvae. Its 1.3-kb transcript undergoes poly-A tail shortening during development, indicating that post-transcriptional controls as well as transcription activation are involved in the temporal regulation of the BhB10-1 gene. Analysis of the deduced amino acid sequence from the cDNA indicates that the BhB10-1 protein is a glycine-rich secretory protein. A BhB10-1-fusion protein expressed in bacteria was used to raise polyclonal antibodies. Using an immunopurified antibody, we identified the product of the DNA puff BhB10-1 gene as a 23-kDa polypeptide that is produced mainly by the salivary gland regions S1 and S3 and is present in the saliva of late larvae. This is the first direct identification of a protein encoded by a DNA puff amplified gene.

Amino Acid Sequence↗
PubMed1999

Non-goblet cell population of Barrett's esophagus: an immunohistochemical demonstration of intestinal differentiation.

Barrett's esophagus develops with the following 2 distinct types of lining mucosa: with and without specialized intestinal metaplasia (SIM). Goblet cells found only in SIM areas identify an intestinal phenotype, recognized as the histological hallmark diagnosing Barrett's metaplasia, and selecting high-risk patients for endoscopic surveillance. The columnar non-goblet cells are the major component of the heterogeneous Barrett's metaplastic cell population and are present in areas either with or without SIM. Their significance in the differentiation of columnar-lined esophagus, and their relationship to malignancy, is still unclear. This immunohistochemical study used two markers of enterocytic differentiation, to explore the intestinal phenotype of the non-goblet cell population of Barrett's epithelium and Barrett's-associated adenocarcinoma cells. Sucrase-isomaltase (SI) and dipeptidilpeptidase IV (DPP) immunoexpression was assessed in paraffin-embedded samples of 12 surgical specimens containing Barrett's esophageal mucosa in association with adenocarcinoma/high grade dysplasia. Ileal mucosa and mucosa from normal gastric and esophageal segments of the surgical specimen were used as positive and negative controls, respectively. SI and DPP were expressed by the neoplastic cells and the columnar non-goblet, being negative in goblet cells. The localization of the enzymes was predominantly apical for SI and cytoplasmatic for DPP. There was immunoreactivity for SI in 58.3% of the carcinomas and in 66.6% of Barrett's mucosa, with equal frequency in areas with and without SIM. DPP was identified in 66.6% of the carcinomas, in 50% of the cases of Barrett's metaplasia with SIM, and in 75% of those without SIM. The columnar non-goblet cell components of Barrett's metaplasia contain small intestine enzymes in the areas either with or without SIM, which suggests that they identify an "incomplete form" of intestinal metaplasia. The demonstration that the two enzymes, SI and DPP, are produced by the columnar non-goblet cell metaplastic population and by the neoplastic cells of the associated adenocarcinoma, indicates that, in addition to the goblet cells, the non-goblet elements may also be involved in the malignant transformation of Barrett's esophagus.

Adenocarcinoma↗
PubMed1998

Short segments of Barrett's epithelium and intestinal metaplasia in normal appearing oesophagogastric junctions: the same or two different entities?

BACKGROUND: Endoscopic diagnosis of short segments of Barrett's epithelium (SSBE)' is difficult and its meaning in terms of the presence of specialised columnar epithelium (SCE) has not been prospectively evaluated. AIMS: To evaluate the prevalence of SCE in patients with an endoscopic diagnosis of SSBE and in individuals with normal appearing oesophagogastric junctions, and to compare the clinical characteristics of these two groups. PATIENTS: Thirty one patients with an endoscopic diagnosis of short Barrett's oesophagus, less than 3 cm in length (group A), and 44 consecutive patients with normal appearing oesophagogastric junctions (group B). METHODS: Multiple biopsies were performed in suspicious epithelium and at the oesophagogastric junction in groups A and B, respectively. RESULTS: Age and sex distribution were similar in both groups. Reflux symptoms were more frequent in group A (p < 0.001), as were endoscopic and histological signs of oesophagitis (p < 0.001 and p = 0.001, respectively). SCE was found in 61.3% of group A patients compared with 25% in group B (p < 0.002), with men predominating in group A while women were more frequent in group B (p = 0.02). The differences in reflux symptoms and endoscopic/histological oesophagitis remained significant. CONCLUSIONS: These results show that endoscopic diagnosis of SSBE is associated with a high prevalence of SCE, significantly higher than that found in normal appearing oesophagogastric junctions. Differences between patients with SCE in the two groups suggest they may represent two different entities.

Aged↗
PubMed1997

Partial characterization of cytoplasmic compartments involved in the endocytic process of Tritrichomonas foetus.

The endocytic pathway of Tritrichomonas foetus, a parasitic protozoan of cattle, was studied using (a) vital dyes, such as Lucifer yellow, neutral red and acridine orange, (b) cationized ferritin, (c) gold-labeled lactoferrin and lectins: HPA, UEA, PNA and LPA, and (d) DAMP (3-(2,4-dinitroanilino) 3' amino-N-methyldipropylamine). Light and confocal laser microscopy as well as transmission electron microscopy were used in this study. Assays were monitored by fluorescence and electron microscopy after exposing the parasites to different conditions. Cells that were incubated at 15 degrees C or 20 degrees C with gold-labeled lactoferrin and processed for electron microscopy show that of 15 degrees C this ligand is found only in an early endosomal compartment and at 20 degrees C it is found in late endosomes but not in lysosomes. Immunocytochemical data from cryosections using DAMP as a pH probe show that T. foetus has acidic compartments, with a pH range of 5.2 to 6.6, with variable morphology, localization and size. Lectin-binding sites and anionic sites were also internalized and appear to be associated with membranes lining the vacuoles. Images of patching and shedding of these sites were also observed when HPA and UEA were used.

Animals↗
PubMed1996

Xp-duplications with and without sex reversal.

Duplications in Xp including the DSS (dosage sensitive sex reversal) region cause male to female sex reversal. We investigated two patients from families with Xp duplications. The first case was one of two sisters with karyotype 46,XY,der(22),t(X;22)(p11.3;p11)mat and unambiguous female genitalia. The living sister was developmentally retarded, and showed multiple dysmorphic features and an acrocallosal syndrome. The second case was a boy with a maternally inherited direct duplication of Xp21.3-pter with the breakpoint close to the DSS locus. He had multiple abnormalities and micropenis, but otherwise unambiguous male genitalia. We performed quantitative Southern blot analysis with probes from Xp22.13 to p21.2 to define the duplicated region. Clinical, cytogenetic, and molecular data from both patients were compared with those of previously reported related cases. A comparison of the extragenital symptoms revealed no differences between patients with or without sex reversal. In both cases, the symptoms were non-specific. Among 22 patients with a duplication in Xp, nine had unambiguous female genitalia and a well-documented duplication of the DSS region. Two patients with duplication of DSS showed ambiguous external genitalia. From these data, we conclude that induction of testicular tissue may start in these patients, but that the type of genitalia depends on the degree of subsequent degeneration by a gene in DSS.

Abnormalities, Multiple↗
PubMed1995

Autosomal dominant osteosclerosis type Stanescu: the third family.

We describe a family with Stanescu osteosclerosis. The propositus and his mother were short and had cortical sclerosis of the long bones, deficient facial sinus development, cranial bone malformations, and normal intelligence. To the best of our knowledge, only two such families have been described previously. The autosomal dominant pattern of inheritance of this skeletal dysplasia is reinforced, as there are many other reportedly affected relatives, including the maternal grandfather, uncles, and aunts of the propositus. The findings of wormian bones and calcification of the falx, not previously described, may be added to the phenotype.

Adult↗
PubMed1995

[The curative surgery of periampullary tumors. The results of 48 resections].

Periampullary tumors form a clinical entity with common symptoms, similar therapeutic options, unsatisfactory resectability rates and unfavorable prognosis. From April 1970 until March 1994, one hundred and twenty-seven patients with periampullary carcinoma were operated by our surgical team. In 48 of these patients, a resection for cure was performed (38%). Resectability rates varied according to the origin of these tumors, i.e., pancreas-20%, ampulla-76%; distal bile duct-71%, periampullary duodenum-88%. Pancreatic tumors showed a different resectability rate from the other periampullary carcinomas (p = 0.04). Forty-two of these patients had a pancreatoduodenectomy and in the remaining 6 cases a total pancreatectomy was performed. Fifteen patients had major post-operative morbidity (31%) and 8 of these cases died in-hospital (17%). Follow-up data was available in 81% of the patients, survival estimates were calculated according to the Kaplan-Meier method and survival comparisons were made with the Log-rank test. Median survival for resected pancreatic carcinoma was 6 months and for resected tumors of the ampulla 37 months. In this group of patients, pancreatic tumors showed a different survival rate from the remaining periampullary tumors (Log-rank-p = 0.002). This work evidences the need to improve management of periampullary tumors, particularly in-hospital mortality and long-term survival. To achieve these goals, patients with periampullary tumors should be treated in specialized centers and research to improve local and systemic control of this disease should be pursued.

Aged↗
PubMed1993

Limb deficiency with or without Möbius sequence in seven Brazilian children associated with misoprostol use in the first trimester of pregnancy.

Misoprostol, a synthetic analog of prostaglandin, has been widely used in Brazil as an abortifacient. Abortion is illegal in Brazil. An uncertain number of these abortion attempts are unsuccessful and the pregnancy continues. We report on 7 patients whose mothers attempted to abort using this drug in the first trimester of gestation without success. The 7 patients presented with limb defects and in 4 of them a diagnosis of Möbius sequence was made.

Abnormalities, Drug-Induced↗
PubMed1993

[Palliative surgery in carcinoma of the stomach. Retrospective study of 112 consecutive cases].

From January 1980 until October 1991 we operated 112 patients with Gastric cancer in which Surgery was considered palliative by intra-operative criteria or by pathological analysis of the resected specimen. Locally irresectable tumour was found in 24.1% of the cases, peritoneal metastases (mets.) in 21.4%, liver mets. in 17%, lymphatic mets. in 16.1%, and other mets. in 21.4%. Resections were possible in 57 patients (50.8%), with a mortality rate of 10.5%, which was similar to the mortality in the non-resection group (7%) p = 0.2. Median survival for the entire group was 7 months, the non-resection group had a median survival of 4 months, and the resection group of 18 months (p = 6.480 e-0.7). Locally advanced tumors had a better outcome than the metastatic group (p = 0.05), but no difference was observed between patients with liver or peritoneal mets. Patients in stage 3 and 4 of the disease had a different prognosis (p = 0.03), and the resection group within each stage fared better.

Adult↗
PubMed1993

Immunoscintigraphy with 99mTc-labelled anti-CEA monoclonal antibody in colorectal carcinoma.

With the introduction of immunoscintigraphy (IS) with 99mTc-labelled anti-CEA monoclonal antibodies (MoAb), a clinical relevant method in nuclear medicine can be expected in the diagnosis and follow up of colorectal cancers. We performed IS (whole body, planar and SPECT) with a 99mTc-labelled intact anti-CEA MoAb (BW 431/26) in 18 patients with primary colorectal carcinoma, metastases or suspicious recurrences from colorectal carcinoma. The results of anti-CEA IS, serum CEA and Ca 19-9 levels were evaluated. Immunoscintigraphy yielded an overall sensitivity of 70.0%, 37.5% for primary tumors, 75.0% for recurrences and 100% for distant metastases. Serum CEA levels were elevated in 10 out of 18 patients (sensitivity 55.5%) and Ca 19-9 were elevated in eight out of 18 patients (sensitivity 44.4%). In the group of patients with metastases, CEA had a sensitivity of 100% and Ca 19-9, of 83.3%. From this prospective study, we can conclude that IS with 99mTC-BW 431/26 is a reliable tool in the post-operative follow-up study of patients with colorectal carcinoma, namely in the detection of distant metastases.

Aged↗
PubMed1992

RAPADILINO syndrome.

We report on a boy with severe radial hypoplasia, absent thumbs and patellae, short stature, persistent diarrhea, slender nose and normal intelligence as another example of the RAPADILINO syndrome.

Abnormalities, Multiple↗