Perforaciones colónicas. Factores pronósticos / Colonic peforations. Prognostic factors

Objetivos. El objetivo principal del estudio fue valorar la influencia de diferentes factores de riesgo sobre la mortalidad de los pacientes, la influencia de dichos factores sobre la supervivencia en las perforaciones tumorales y finalmente comparar los resultados del grupo de perforaciones de etiología maligna con el de etiología benigna. Pacientes y métodos. En el presente estudio retrospectivo multicéntrico se presenta la experiencia de tres hospitales de la Comunidad Valenciana (Hospital General de Castellón, Hospital Gran Vía de Castellón y Hospital Comarcal de Vinaroz) en perforaciones de colon durante el período de tiempo comprendido entre enero de 1994 y abril de 1998. Fueron incluidos en el estudio un total de 68 pacientes, 38 varones y 30 mujeres con una edad media de 68 ñ 14 años (rango, 29-90). Se recogieron datos referentes a etiología, comorbilidad, clínica de presentación, exploraciones, hallazgos, técnica operatoria, morbimortalidad y seguimiento. Resultados. Se recogieron 13 etiologías diferentes, siendo la diverticulitis (n = 26; 38,2 por ciento) y las neoplasias (n = 21; 29,4 por ciento) las causas más frecuentes. En cuanto a los hallazgos (grado de contaminación), 17 pacientes (25 por ciento) presentaron abscesos, 15 (22,1 por ciento) peritonitis localizada, 21 (30,9 por ciento) peritonitis purulenta difusa y 15 (22,1 por ciento) peritonitis fecaloidea difusa. La estancia media hospitalaria fue de 18,3 ñ 13,8 días. Presentaron complicaciones postoperatorias 45 pacientes (66,2 por ciento), siendo las más frecuentes la infección de la herida quirúrgica (15; 22,1 por ciento), la evisceración (7; 10,3 por ciento) y el fallo multiorgánico (5; 7,4 por ciento). La mortalidad operatoria fue del 26,6 por ciento (14 pacientes). Conclusiones. La mortalidad perioperatoria es más elevada en aquellos pacientes de mayor edad, con clínica de diarrea al ingreso y a los que no se les practica resección de la zona perforada. La perforación es una complicación grave del cáncer de colon, con una mortalidad alta y mal pronóstico, presentando los pacientes con perforaciones tumorales mayor frecuencia de clínica de distensión abdominal y de complicaciones postoperatorias que aquellos con perforaciones benignas (AU)

La cirugía como tratamiento de una entidad recientemente descrita: linfoma B cutáneo de células de la zona marginal / Surgical treatment of a recently described disease: marginal zone cutaneous B-cell lymphoma

Tras la reciente descripción del linfoma B de células de la zona marginal, el papel de la cirugía en el manejo de los linfomas cutáneos ha pasado de ser de meramente diagnóstico a terapéutico. En este artículo se presenta un caso de linfoma B de células de la zona marginal tratado por nuestro grupo en el que este nuevo esquema terapéutico demostró buenos resultados y la ventaja de la administración de una menor dosis de radioterapia (AU)

Estudio Delphi de la Sociedad Valenciana de Cirugía: tratamiento quirúrgico del cáncer gástrico / A Delphi study by the Surgical Society of Valencia, Spain: surgical treatment of gastric cancer

Se presentan los resultados del primer estudio de consenso auspiciado por la Sociedad Valenciana de Cirugía sobre el tratamiento quirúrgico del cáncer gástrico. Se trata de un esudio tipo Delphi, con la participación de 31 expertos pertenecientes a la mayoría de hospitales de la Comunidad Valenciana. Los temas consensuados han versado sobre los siguientes aspectos: nutrición artificial, métodos de estadificación preoperatoria, tipo de resección y de linfadenectomía, técnicas de reconstrucción, criterios de resecabilidad y temas de organización (AU)

Complexes from Trypanosoma brucei that exhibit deletion editing and other editing-associated properties.

Transcripts from many mitochondrial genes in kinetoplastids undergo RNA editing, a posttranscriptional process which inserts and deletes uridines. By assaying for deletion editing in vitro, we found that the editing activity from Trypanosoma brucei mitochondrial lysates (S.D. Seiwert and K.D. Stuart), Science 266:114-117,1994) sediments with a peak of approximately 20S. RNA helicase, terminal uridylyl transferase, RNA ligase, and adenylation activities, which may have a role in editing, cosediment in a broad distribution, with most of each activity at 35 to 40S. Most ATPase 6 (A6) guide RNA and unedited A6 mRNA sediments at 20 to 30S, with some sedimenting further into the gradient, while most edited A6 mRNA sediments at >35S. Several mitochondrial proteins which cross-link specifically with guide RNA upon UV treatment also sediment in glycerol gradients. Notably, a 65-kDa protein sediments primarily at approximately 20S, a 90-kDa protein sediments at 35 to 40S, and a 25-kDa protein is present at <10S. Most ribonucleoprotein complexes that form with gRNA in vitro sediment at 10 to 20S, except for one, which sediments at 30 to 45S. These results suggest that RNA editing takes place within a multicomponent complex. The potential functions of and relationships between the 20S and 35 to 40S complexes are discussed.

Chemical induction of stress proteins does not induce splicing thermotolerance under conditions producing survival thermotolerance.

Cell survival during a severe heat stress can be enhanced when heat shock proteins are induced prior to the severe heat treatment. Induction can be accomplished either by heat or chemical treatments. The increase in survival at these severe elevated temperatures after pretreatment has been referred to as thermotolerance, which we now refer to as survival thermotolerance. It has also been shown previously that mild heat treatment allows splicing in cells subjected to a severe heat treatment, now referred to as splicing thermotolerance. The experiments shown here demonstrate that even though chemical induction of the heat shock proteins leads to survival thermotolerance, this same treatment does not induce splicing thermotolerance. These are the first results that demonstrate at least two distinct aspects of thermotolerance.

Trypanosoma brucei mitochondrial CR4 gene encodes an extensively edited mRNA with completely edited sequence only in bloodstream forms.

Several kinetoplastid mitochondrial genes cannot be expressed without RNA editing of their transcripts to create a functional open reading frame. We have examined one such mitochondrial gene, CR4, in Trypanosoma brucei EATRO164 and find extensive editing of transcripts in both bloodstream and procyclic life cycle stages. However, a consensus edited sequence for the entire mRNA occurs only in the bloodstream stage. The unedited CR4 transcript is 283 nucleotides in length, not including the poly(A) tail. A total of 325 uridines are inserted, and 40 uridines deleted, to create the mature mRNA which encodes a very hydrophobic protein.

Multiple guide RNAs for identical editing of Trypanosoma brucei apocytochrome b mRNA have an unusual minicircle location and are developmentally regulated.

We identified four different guide RNAs (gRNAs) that specify identical editing of Trypanosoma brucei apocytochrome b (CYb) mRNA, which indicates gRNA redundancy in T. brucei. All four gRNAs appear functional since they occur in chimeras, some of which contain an interesting gRNA 3' "extension." The gRNAs are encoded in different minicircles, rather than maxicircles as in other species. However, these gRNA genes are not between 18-base pair repeats as are the other minicircle gRNA genes in T. brucei. The three minicircles cloned contain the same gRNA genes, one of which is substantially diverged, all in the same order, indicating that they are related. CYb gRNA is less abundant in procyclic than bloodstream forms. Procyclic forms contain abundant edited CYb mRNA unlike bloodstream forms thus suggesting that CYb mRNA editing may be regulated at the level of gRNA utilization.

Trypanosoma brucei minicircles encode multiple guide RNAs which can direct editing of extensively overlapping sequences.

Small guide RNAs (gRNAs) may direct RNA editing in kinetoplastid mitochondria. We have characterized multiple gRNA genes from Trypanosoma brucei (EATRO 164), that can specify up to 30% of the editing of the COIII, ND7, ND8, and A6 mRNAs and we have also found that the non-translated region of edited COIII mRNA of strain (EATRO 164) differs from that of another strain. Several of the gRNAs specify overlapping regions of the same mRNA often specifying sequence beyond that required for an anchor duplex with the next gRNA. Some gRNAs have different sequence but specify identical editing of the same region of mRNA. These data indicate a complex gRNA population and consequent complex pattern of editing in T. brucei.

Splicing thermotolerance maintains Pre-mRNA transcripts in the splicing pathway during severe heat shock.

Thermotolerance, the ability of cells and organisms to withstand severe elevated temperatures after brief exposure to mild elevated temperatures, has been studied in numerous laboratories. Survival thermotolerance is defined as the increase in cell or organism survival at severe elevated temperatures after a pretreatment at mild elevated temperatures. This study examines splicing thermotolerance in Drosophila melanogaster, the ability to splice pre-mRNAs made at the severe temperature (38 degrees C) after a brief pretreatment at a milder temperature (35 degrees C). It is probably one of a number of mechanisms by which cells adapt to heat shock. These experiments demonstrate that pre-mRNAs synthesized at the severe temperatures in splicing thermotolerant cells, although protected in splicing-competent complexes, are not actually processed to mature mRNAs until the cells are returned to their normal temperature. We have also studied the kinetics of acquisition and loss of splicing thermotolerance. As little as 10 min of pretreatment at 35 degrees C was sufficient to provide full splicing thermotolerance to a 30-min severe heat shock of 38 degrees C. Pretreatments of less than 10 min provide partial splicing thermotolerance for a 30-min severe heat shock. Full splicing thermotolerance activity begins to decay about 4 h after the cessation of the 35 degrees C incubation and is completely lost by 8 h after the pretreatment. The kinetics experiments of pre-mRNAs synthesized during the 38 degrees C treatment in splicing thermotolerant cells indicate that one or more splicing thermotolerance factors are synthesized during the 35 degrees C pretreatment which interact with pre-mRNA-containing complexes to keep them in a splicing-competent state. These kinetic experiments also indicate that in cells which are partially splicing thermotolerant, the pre-mRNAs synthesized early during the 38 degrees C incubation are protected, whereas those synthesized late are not. In the absence of splicing thermotolerant factors, the pre-mRNA-containing complexes leave the normal splicing pathway and are allowed to exit to the cytoplasm.

Home total parenteral nutrition in a "no-bowel" patient in Spain.

OBJECTIVE: To report a case of a patient with no functional bowel who was receiving home total parenteral nutrition in a country that has had a few professional experiences in this area of therapy. CASE SUMMARY: A woman with a history of scattered colonic polyposis developed a mesenteric tumor that caused intestinal obstruction. Tumor withdrawal required the excision of 1.5 m of jejunum-ileum. Postoperative complications required further surgical intervention and subtotal intestinal resection. Duodenocolic anastomosis was not possible and a high output and permanent fistula remained. DISCUSSION: The complications of home parenteral nutrition addressed in the literature are reviewed. The problems encountered in our patient have been resolved. CONCLUSIONS: After three years of postoperative survival, we believe the quality of life of our patient has increased and the parenteral nutrition team members are much better prepared to manage patients with similar problems.

Chimeric and truncated RNAs in Trypanosoma brucei suggest transesterifications at non-consecutive sites during RNA editing.

RNA editing adds and removes uridines at specific sites in several mitochondrial transcripts in kinetoplastid parasites probably as specified by guide RNAs (gRNAs) that are complementary to the final edited sequence. Editing has been postulated to involve transesterification which predicts (1) chimeric molecules with a gRNA covalently attached by its non-encoded oligo U tail to an internal editing site in the mRNA and (2) the corresponding truncated 5' portions of the mRNAs. We have characterized cDNAs representing a large number of both types of intermediates from Trypanosoma brucei. The lengths of both U tails and encoded gRNA sequences vary greatly in length. The majority of encoded gRNA sequences are shorter than predicted based on their minicircle coding sequences. Analysis of the predominant sites of gRNA attachment in chimeras suggests that the transesterifications that religate the truncated 5' mRNAs may proceed more rapidly at editing sites at the 5' end of an editing domain and at sites of U deletion. Partially edited sequences in the mRNA portion of chimeras and at the 3' ends of truncated 5' mRNAs also indicate a non-consecutive order of site selection during RNA editing.