Biomedical subjects
Publications and source records attributed to N Flores.
A case of renal adenocarcinoma arising in a 18 year-old boy is reported. This is a rare entity in childhood and adolescence that displays a similar histology to the adult form. The recent literature on its clinical and pathological features is reviewed. We conclude that, despite its rarity, adenocarcinomas must be included in the differential diagnosis of solid renal masses in early life.
We present a case of urinary bladder carcinoma in a child aged 13 that followed a benign course. This confirms the idea that epithelial bladder cancer in children pursues, a much less aggressive behaviour than in the adult, possibly on the basis of its well-differentiated nature. Despite the rarity of the lesion, it should not be overlooked in the differential diagnosis of haematuria in children.
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We have determined the complete nucleotide sequence of a 6.3-kb chromosomal HpaI-EcoRI fragment, that contains the structural genes for both the large and small subunits of the Escherichia coli K-12 glutamate synthase (GOGAT) enzyme, as well as the 5'- and 3'-flanking and intercistronic DNA regions. The Mrs of the two subunits, as deduced from the nucleotide (nt) sequence, were estimated as 166,208 and 52,246. Partial amino acid sequence of the GOGAT enzyme revealed that the large subunit starts with a cysteine residue that is probably generated by a proteolytic cleavage. Northern blotting experiments revealed a transcript of approximately 7300 nt, that at least contains the cistrons for both subunits. A transcriptional start point and a functional promoter were identified in the 5' DNA flanking region of the large subunit gene. The messenger RNA nontranslated leader region has 120 nt and shares identity with the leader regions of E. coli ribosomal operons, in particular around the so-called boxA sequence implicated in antitermination. Other possible regulatory sequences are described.
The plasmid pBR322 was one of the first EK2 multipurpose cloning vectors to be designed and constructed (ten years ago) for the efficient cloning and selection of recombinant DNA molecules in Escherichia coli. This 4363-bp DNA molecule has been extensively used as a cloning vehicle because of its simplicity and the availability of its nucleotide sequence. The widespread use of pBR322 has prompted numerous studies into its molecular structure and function. These studies revealed two features that detract from the plasmid's effectiveness as a cloning vector: plasmid instability in the absence of selection and, the lack of a direct selection scheme for recombinant DNA molecules. Several vectors based on pBR322 have been constructed to overcome these limitations and to extend the vector's versatility to accommodate special cloning purposes. The objective of this review is to provide a survey of these derivative vectors and to summarize information currently available on pBR322.
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Measurement of myocardial blood flow and assessment of coronary calibre in man has important clinical and research value. An inexpensive microcomputer system has been developed to facilitate analysis of each of these. Coronary sinus and great cardiac vein blood flow are measured using the thermodilution technique. The output of the temperature measurement circuitry is digitized and used to calculate blood flows. For coronary artery calibre measurement, the outline of an arterial segment recorded during coronary arteriography is digitized manually. The microcomputer system provides a graphic display of the digitized artery and calculates diameters throughout its length. Excellent correlations were observed between computer and manual methods for both systems.
We report on a patient with von Hippel-Lindau disease with special reference to the urological features. Several members of the patient's family had also presented this hereditary disease. Careful follow-up of these patients permits early diagnosis of some of the characteristic tumors. Because it has a tendency to be multifocal and bilateral, surgical treatment of renal carcinoma must be as conservative as possible. For this reason, early tumor excision constitutes the ideal treatment. The importance of family screening and genetic counselling is underscored.
We report two cases of bladder leiomyosarcoma diagnosed by histology. Total segmental cystectomy was performed in both cases because of the scant progressive nature of the disease. A follow up of 11 and 6 years, respectively, revealed no tumor recurrence or metastasis. The choice of performing a conservative or radical surgical procedure in the treatment of this tumor type should depend on the endoscopic findings as well as tumor grade and stage.
We present two cases of angioma of the glans penis and we reviewed this disease entity from a clinical and therapeutic points of view, classically understood as a proliferative process of a malformative nature. However, both cases that are described can be interpreted as true vascular tumors of a benign nature.
Contribution of one case of malignant testicular mesothelioma. A highly malignant tumour the diagnosis and specific treatment of which is not clearly defined. The correct diagnosis should be based on a series of features not only clinical (quick re-accumulation of liquid in the inverted hydrocele) but also gross (multiple paratesticular nodes) and microscopic, supported by immunohistochemical techniques. The latter is based both in ruling an adenocarcinoma out (CEA-, LeuM1-, Vimentine- to tumoral cells), and in the reactivity of more specific antigens (CAM5.2(K-8)+ and Vimentine+ to stromal cells). The choice treatment is inguinal orchiectomy with adjuvant chemotherapy. No standard chemotherapeutical approaches have been defined.