Influencias de la actividad humana sobre la costa de la ciudad de Comodoro Rivadavia, prov. de Chubut, Argentina

Se analizan las variaciones inducidas por la actividades humanas en la costa de la ciudad de Comodoro Rivadavia, prov. de Chubut. Comparando las fotografías aéreas de la zona portuaria de la ciudad, surge un ritmo de erosión de 1,2 m/año para el intervalo 1983-1995. El artículo analiza las causas de esta erosión y concluye que la principal causante, es la falta de provisión de sedimentos

Influencias de la actividad humana sobre la costa de la ciudad de Comodoro Rivadavia, prov. de Chubut, Argentina

Se analizan las variaciones inducidas por la actividades humanas en la costa de la ciudad de Comodoro Rivadavia, prov. de Chubut. Comparando las fotografías aéreas de la zona portuaria de la ciudad, surge un ritmo de erosión de 1,2 m/año para el intervalo 1983-1995. El artículo analiza las causas de esta erosión y concluye que la principal causante, es la falta de provisión de sedimentos

Contenido en algunos nutrientes del alga marina comestible Monostroma undulatum Wittrock de la costa patagónica argentina / Chemical composition and seasonal fluctuations of the edible green seaweed, Monostroma undulatum, Wittrock, from the Southern Argentina coast

The chemical composition of green seaweed, Monostroma undulatum, Wittrock, growing in the Southern Argentina coast, was studied. Samples were collected in Puerto Deseado, province of Santa Cruz (47 degrees 45'L.S., 65 degrees 55'L.W.), from October to December 1999 and 2000. It has been analyzed six sample during this period. Algae were washed with sea water and dried at room temperature for 24 hs. Moisture, nitrogen, lipids and ashes were determined according to AOAC; fiber (total, soluble and insoluble), according to Lahaye. After mineralization with nitric acid, sodium and potassium were determined by flame photometry, calcium by complexometric method, and phosphorus by Gomori's method. The ranges expressed per 100 g dry algae were: protein (Nx6.25): 12.89-21.85; ashes (g): 33.92-40.05; lipid (g): 0.32-1.47; total fiber (g): 14.36-19.6; digestible carbohydrates (calculated by difference) (g): 20.86-32.48; sodium (g): 7.39-13.11; potassium (g): 1.38-3.18; calcium (mg): 149-226; phosphorus (mg): 190-447; Vitamin C (mg): 159-455. These results show that this green seaweed is an important source for protein, fiber, macronutrients minerals and vitamin C, during the macroscopic period. There was an important fluctuation that must be taken into account to consider the commercial collection to use it in human nutrition.

A sequence-specific RNA binding complex expressed in murine germ cells contains MSY2 and MSY4.

The protamine mRNAs are stored for up to 8 days as translationally repressed ribonucleoprotein particles during murine spermatogenesis. Translational repression of the protamine 1, Prm1, mRNA is controlled by sequences in its 3'-untranslated region (UTR). In this study we used the yeast three-hybrid system to clone Msy4, which encodes a novel member of the Y box family of nucleic acid binding proteins. MSY4 specifically binds to a site within the 5' most 37 nucleotides in the Prm1 3' UTR. Msy4 is highly expressed in the testis, and the protein is detected in the cytoplasm of germ cells in both the testis and the ovary, where repressed messages are stored. Analysis of a previously described 48/50-kDa binding activity in testis extracts by electrophoretic mobility shift assays and immunoprecipitation indicates the activity is composed of MSY4 and MSY2, another mouse Y box protein. Polysome analysis demonstrates MSY4 is associated with mRNPs, consistent with MSY4 having a role in storing repressed messages.

[Contents of various nutrients, minerals and seasonal fluctuations in Porphyra columbina, an edible marine algae from the Argentine Patagonian++ coast]. / Contenido de algunos nutrientes, minerales y variaciones estacionales en Porphyra columbina, alga comestible de la Costa Patagónica argentina.

Porphyra columbina (Rodophyta Bangiales), one of the most important edible seaweeds, grows abundantly in the southern Argentine coast. Their mineral content and seasonal fluctuations were determined because there is no national data about their nutritional value. Samples were collected from April 1993 to February 1994 from Golfo San Jorge (30 Km South of Comodoro Rivadavia). Algae were washed with sea water and dried at room temperature (20-2 degrees C) for 24 hs, following the local processing procedure. Moisture and ashes were determined according to A.O.A.C. After mineralization with nitric acid sodium and potassium were determined by flame photometry; calcium, magnesium and iron by atomic absorption spectrophotometry (AAS); and phosphorus by Gomori's method. The results, expressed per 100 g dry algae showed the following values: moisture content: 7.03 to 11.00 g/100 g; ashes: 16.18 to 22.70 g/100 g; sodium: 3.18 to 6.41 g/100 g; potassium 1.24 to 1.96 g/100 g; magnesium: 600 to 836 mg/100 g; phosphorus: 78 to 276 mg/100 g; calcium: 63 to 108 mg/100 g and iron: 3.9 to 26.4 mg/100 g. The results of composition of algae as manufactured in the region showed important seasonal differences, with the highest values of ashes, sodium, potassium and magnesium in winter season (June and July).

Separate elements in the 3' untranslated region of the mouse protamine 1 mRNA regulate translational repression and activation during murine spermatogenesis.

The mouse protamine mRNAs, Prm-1 and Prm-2, are translationally repressed for several days during male germ cell differentiation. The translational delay of mouse Prm-1 mRNA has previously been shown to be dependent upon cis-acting elements that reside in the last 62 nucleotides of the Prm-1 3' untranslated region (3' UTR). We have previously identified a 48/50-kDa protein that binds the 3' UTRs of both Prm-1 and Prm-2 mRNAs in a sequence-specific manner, is present in cytoplasmic fractions of postmeiotic round spermatids where the protamine mRNAs are translationally silent, and is markedly reduced in elongated spermatids where the protamine mRNAs become activated for translation. Surprisingly, the binding site for this activity maps to a region of the Prm-1 3' UTR not contained within the functional 62 nucleotides described above. In this report we show that the binding site for the 48/50-kDa protein can also delay translation of a reporter RNA in vivo, suggesting that the 48/50-kDa protein can repress the translation of Prm-1 mRNA during murine spermatogenesis. This observation proves that two separate regions of the Prm-1 3' UTR are sufficient to repress Prm-1 translation. In addition, immunocytochemistry and polysome analysis have revealed that this transgenic reporter mRNA fails to undergo proper translational activation. These results suggest that an additional region of the Prm-1 3' UTR is required for proper translational activation and that Prm-1 translational repression elements can be separated from those involved in translational activation.

Adenosquamous carcinoma arising in a mucinous cystadenoma of the pancreas.

BACKGROUND: Approximately 500 cystic neoplasms of the pancreas have been reported, and among these the mucinous pancreatic cystadenomas are known to have malignant potential. We report a rare case of a mucinous cystadenoma containing adenosquamous carcinoma. METHODS: We studied the histochemical and immunohistochemical staining characteristics of the tumor by staining with hematoxylin/eosin, Alcian Blue/Periodic Acid Schiff, and with immunoperoxidase-labelled antibodies against carcinoembryonic antigen, epithelial membrane antigen, low and high molecular weight cytokeratins, the proliferation antigen Ki-67, and the tumor suppressor antigen p-53. The K-ras oncogene was analyzed by direct sequencing. RESULTS: This case illustrates the usual presentation and features of this unusual tumor-a middle aged woman with abdominal pain and no history of alcohol abuse or abdominal trauma. The mucinous cystic tumor of her pancreas was composed predominantly of benign epithelium with areas of a malignant component that were identified by thorough sampling. CONCLUSION: We discuss the nomenclature of these neoplasms and suggest that continuing efforts to subclassify mucinous cystic pancreatic tumors histologically may not be necessary, since the tumors are all histologically similar and are malignant or have malignant potential, and for all, treatment should include resection.

A testis cytoplasmic RNA-binding protein that has the properties of a translational repressor.

Translation of the mouse protamine 1 (Prm-1) mRNA is repressed for several days during male germ cell differentiation. With the hope of cloning genes that regulate the translational repression of Prm-1, we screened male germ cell cDNA expression libraries with the 3' untranslated region of the Prm-1 RNA. From this screen we obtained two independent clones that encode Prbp, a Prm-1 RNA-binding protein. Prbp contains two copies of a double-stranded-RNA-binding domain. In vitro, the protein binds to a portion of the Prm-1 3' untranslated region previously shown to be sufficient for translational repression in transgenic mice, as well as to poly(I). poly(C). Prbp protein is present in multiple forms in cytoplasmic extracts prepared from wild-type mouse testes and is absent from testes of germ cell-deficient mouse mutants, suggesting that Prbp is restricted to the germ cells of the testis. Immunocytochemical localization confirmed that Prbp is present in the cytoplasmic compartment of late-stage meiotic cells and haploid round spermatids. Recombinant Prbp protein inhibits the translation of multiple mRNAs in a wheat germ lysate, suggesting that Prbp acts to repress translation in round spermatids. While this protein lacks complete specificity for Prm-1-containing RNAs in vitro, the properties of Prbp are consistent with it acting as a general repressor of translation.

Germ cell-specific proteins interact with the 3' untranslated regions of Prm-1 and Prm-2 mRNA.

The testis-specific mouse protamine genes (Prm-1 and Prm-2) are transcribed in haploid round spermatids, their mRNAs stored as cytoplasmic ribonucleoprotein particles and translated about 1 week later in elongating spermatids. We have compared the in vitro translational efficiencies of deproteinized Prm-1 mRNA isolated from purified populations of germ cells and found that Prm-1 mRNA from round spermatids translates as efficiently as Prm-1 mRNA from elongating spermatids, suggesting that translation of Prm-1 mRNA is normally repressed in round spermatids. Previous studies in transgenic mice have shown that the 3' UTR of Prm-1 mRNA is necessary and sufficient for its translational control (Braun et al., 1989). In this manuscript, we have used an RNA band shift assay to identify an activity, present in cytoplasmic fractions of meiotic spermatocytes and postmeiotic round spermatids, that binds the 3'UTRs of both Prm-1 and Prm-2 mRNA. We have used 3' UTR deletion variants to map the binding site to a 22-nt region within the Prm-1 3' UTR and to a 20-nt region within the Prm-2 3' UTR. uv cross-linking of the RNA band shift activities detected with the Prm-1 and Prm-2 3' UTRs generated the same two RNA/protein complexes of 53 and 55 kDa. The presence of the binding activity in the cell type and subcellular compartment associated with Prm-1 and Prm-2 mRNA storage suggest that the activity may be actively engaged in translational repression of these mRNAs.

Avoiding complications and decreasing costs of central venous catheter placement utilizing electrocardiographic guidance.

A technique for electrocardiographic (ECG) guided percutaneous placement of central venous catheters (CVC) was studied in a prospective, randomized manner. In 34 patients, 51 ECG guided percutaneous CVC were compared with 29 blind percutaneous CVC in 23 patients. Thirty-nine percent of CVC placements were changes over a guide wire. Ideal catheter tip location at the atriocaval junction was achieved in 96 percent of the patients in the study versus 59 percent of those in the control group (p less than 0.001). In addition, we report 25 patients with open placement of CVC using intraoperative ECG guidance and fluoroscopic confirmation. Ideal location of the catheter tip was achieved in 100 percent of these patients. ECG guided CVC placement using the technique described herein obviates the need for catheter repositioning, repeat roentgenographic studies and intraoperative fluoroscopic imaging, along with the attendant costs and radiation exposure to staff and patient. Aberrant catheter tip placement and the associated morbidity are also eliminated.

Serological identification of thymocyte differentiation antigens.

We have examined subfractions of human thymocytes for the expression of novel differentiation antigens. Non-HLA alloantisera procured from multiparous women served as antibody probes. Thymocytes from five individuals were sequentially separated by discontinuous Percoll density gradient centrifugation and a peanut agglutinin (PNA) panning technique. Subfractions were selected and examined for their relative intensity of HLA class I and CD1 antigens as determined by cytofluorometric analysis. Two subfractions were characterized as follows: an immature population (Fr6 PNA-) expressed a high level of CD1 (OKT6 binding) antigen and a low level of class I HLA antigen; and a more mature fraction (Fr3 PNA-) expressed minimal amounts of CD1 antigen and relatively high levels of HLA class I molecules. Fr6 PNA+ and Fr3 PNA- thymocytes were tested for their reactivity with a panel of non-HLA alloantibodies as determined by cytofluorometric analysis. We observed that three alloantibodies demonstrated strong fluorescence staining with Fr6 PNA+ thymocytes only, whereas three other alloantibodies reacted with both the Fr6 PNA+ and the Fr3 PNA- subfractions. All six alloantibodies failed to react with peripheral T cells. However, the six antibodies did react with a panel of cultured T lymphoblastoid leukemic cells and fresh leukemic T cells. Blocking studies demonstrated that these alloantibodies do not bind beta 2-microglobulin-associated determinants. These results suggest that the alloantibodies detect thymocyte differentiation antigens (TDA) that are shared by or are cross-reactive with antigens expressed on certain leukemia T cells. The non-beta 2m-associated TDA antigens are not expressed on normal resting T cells.