Differential tissue distribution of discrete typing units after drug combination therapy in experimental Trypanosoma cruzi mixed infection.

The aim of the present work was to evaluate the distribution of the different clones of the parasite prevailing after treatment with benznidazole (BZ) and clomipramine (CLO), in mice infected with Trypanosoma cruzi, Casibla isolate which consists of a mixture of two discrete typing units (DTUs). Albino Swiss mice were infected and treated with high and low concentrations of BZ (100 or 6.25 mg/kg), CLO (5 or 1.25 mg/kg), or the combination of both low doses (BZ6.25 + CLO1.25), during the acute phase of experimental infection. Treatment efficacy was evaluated by comparing parasitaemia, survival and tissular parasite presence. For DTUs genotyping, blood, skeletal and cardiac muscle samples were analysed by multiplex quantitative polymerase chain reaction. The combined treatment had similar outcomes to BZ6.25; BZ100 was the most effective treatment, but it failed to reach parasite clearance and produced greater histological alterations. Non-treated mice and the ones treated with monotherapies showed both DTUs while BZ6.25 + CLO1.25 treated mice showed only TcVI parasites in all the tissues studied. These findings suggest that the treatment may modify the distribution of infecting DTUs in host tissues. Coinfection with T. cruzi clones belonging to different DTUs reveals a complex scenario for the treatment of Chagas disease and search for new therapies.

Differential tissue distribution of Trypanosoma cruzi during acute experimental infection: Further evidence using natural isolates.

In the present work, we evaluated the effect of mixed Trypanosoma cruzi infections, studying the biological distribution of the different parasites in blood, heart and skeletal muscle during the acute phase. Albino Swiss mice were infected with different parasite strain/isolates or with a combination of them. The parasites in the different tissues were typified through specific PCR, population variability was analyzed through RFLP studies and parasitological and histopathological parameters were evaluated. We found a predominance of TcII and TcVI in all tissues samples respect to TcV and different parasite populations were found in circulation and in the tissues from the same host. These results verify the distribution of parasites in host tissues from early stages of infection and show biological interactions among different genotypes and populations of T. cruzi.

Trypanothione reductase inhibitors: Overview of the action of thioridazine in different stages of Chagas disease.

Thioridazine (TDZ) is a phenothiazine that has been shown to be one of the most potent phenothiazines to inhibit trypanothione reductase irreversibly. Trypanothione reductase is an essential enzyme for the survival of Trypanosoma cruzi in the host. Here, we reviewed the use of this drug for the treatment of T. cruzi experimental infection. In our laboratory, we have studied the effect of TDZ for the treatment of mice infected with different strains of T. cruzi and treated in the acute or in the chronic phases of the experimental infection, using two different schedules: TDZ at a dose of 80 mg/kg/day, for 3 days starting 1h after infection (acute phase), or TDZ 80 mg/kg/day for 12 days starting 180 days post infection (d.p.i.) (chronic phase). In our experience, the treatment of infected mice, in the acute or in the chronic phases of the infection, with TDZ led to a large reduction in the mortality rates and in the cardiac histological and electrocardiographical abnormalities, and modified the natural evolution of the experimental infection. These analyses reinforce the importance of treatment in the chronic phase to decrease, retard or stop the evolution to chagasic myocardiopathy. Other evidence leading to the use of this drug as a potential chemotherapeutic agent for Chagas disease treatment is also revised.

Circulating Trypanosoma cruzi populations differ from those found in the tissues of the same host during acute experimental infection.

We evaluated the presence and distribution of two Trypanosoma cruzi natural isolates in blood, heart, skeletal muscle, liver, and spleen tissues in the acute phase of the experimental infection (35 days postinfection) in order to determine if the populations present in blood were different to those found in the tissues of the same host. Thirty mice were infected with 50 forms of each isolate or with a combination of them. Presence and molecular characterization of the parasites in the host tissues were determined by specific PCR. Cardiac and skeletal muscle alterations were analyzed by histological studies. T. cruzi variability in the host tissues was analyzed through RFLP studies. Both isolates used consisted of a mixture of two T. cruzi lineages. Specific PCRs were positive for most of the samples from the 3 groups analyzed. Cardiac and skeletal muscle sections from the groups infected with one isolate presented mild to moderate inflammatory infiltrates; the group infected with both isolates showed severe inflammatory infiltrates and the presence of amastigote nests in both tissues. Different parasite populations were found in circulation and in the tissues from the same host. These results are important for patients with high probability of mixed infections in endemic areas and contribute to the knowledge of parasite/host interactions.

Estudio basal de prevalencia de sífilis y vih y comportamientos asociados en población privada de libertad, Perú 1999 / Basal studies on syphilis and HIV prevalence and associated behaviors related to imprisoned population, Peru 1999

Objetivo: Estimar la prevalencia de sifilis y vih e identificar los comportamientos de riesgos asociados en personas privadas de libertad (PPL). Materiales y métodos: Estudio transversal realizado durante el año 1999 en 22 establecimientos penitenciarios peruanos. Se realizó RPR para la detección de sífilis (datos ligados) y ELISA para tamizaje de vih (datos no ligados), confirmándose con IFI o Western Blot. Se realizó una encuesta estructurada y se analizaron los datos mediante los programas SPSS 9,0 y AMOS 4. Resutados: Particparon 6 963 PPL. La prevalencia de vih fue 1,1 por ciento y de sífilis 4,1 por ciento. Los comportamiento de riesgo asociados a vih más significativos fueron: consumo de drogas (OR:2,7), infecciones de transmisión sexual (OR:2,3), relaciones sexuales entre hombres (OR:2,2), uso de cocaína (OR: 2,1), úlcera genital (OR: 2,1), haber sido encarcelado previamente (OR: 2) y tener tatuajes (OR: 1,99). Mientras los asociados a sífilis fueron: tener relaciones sexuaqles entre hombres (OR: 2,8), infecciones de transmisión sexual (OR:2,4), úlcera genital (OR 1,8), haber tenido relaciones sexuales con trabajadora sexual (OR:1,5) y tener más de dos parejas sexuales (OR: 1,5). Utilizando un modelo de ecuaciones estructurales se asoció VIH con el reporte de tener tatuaje, más de dos parejas sexuales, mós de un encarcelamiento previo y úlcera genital. Conclusiones: Se encontraron importantes valores de prevalencia de VIH y sífilis en este grupo de personas, siendo necesario continuar realizando estudios similares que nos permitan conocer las tendencias (vigilancia de segunda generación) y conocer el impacto de posibles intervenciones

[Modalities of mechanical ventilation]. / Modalidades de ventilación mecánica]

Mechanical ventilation improves the symptoms and reduces complications of acute respiratory failure. Recent advances in microprocessor technology have increased the sophistication of mechanical ventilators, thus leading to new ventilation modalities. This article describes the ventilation modalities available, grouping them as conventional, alternative and new modalities. Conventional ventilation includes the most widely used modalities, alternative ventilation includes less frequently used modalities, and new ventilation modalities include recently introduced options that are available on the latest-generation mechanical ventilators.

[Ventral hernia surgery]. / Chirurgia dei laparoceli.

BACKGROUND: A personal technique for polypropilene mesh implantation in the treatment of massive, boundary and recurrent incisional hernias is described. METHODS. DESIGN: retrospective evaluation of cases observed over the last 3 years. SETTING: division of General, Oncological and Thoracic Surgery, Department of Surgical and Anatomical Sciences, University of Palermo. SUBJECTS: twenty-four patients with massive, boundary and recurrent ventral hernia were selected and treated with this technique. INTERVENTIONS: the patients were submitted to implantation of a polypropilene prosthesis by using a part of the well vascularised hernial sac in order to close completely the peritoneal layer under the prosthesis (so as to avoid the contact between prosthesis and viscera) and to close the layer over the prosthesis (avoiding a contact between prosthesis and subcutis). MAIN OUTCOME MEASURES: morbidity and mortality have been evaluated. RESULTS: Patients were discharged from the 7th and 15th postoperative day. No mortality was recorded. In four out of 24 patients the following complications were observed: 1 case of high postoperative fever; 2 cases of superficial infection of the surgical wound; 1 case of wide cutaneous suppuration without prosthesis involvement. No recurrences were observed during the follow-up (6 months-3 year). CONCLUSIONS: Even if a scientific evaluation of the results is not possible due to the poor number of cases, short-term follow-up and unavailable randomized studies, this technique may be useful since it permits to avoid the contact between prosthesis and viscera, with lower postoperative adherences and the isolation of prosthesis from the subcutaneous tissue, sometimes involved in suppuration.

Monitorización del paciente en ventilación mecánica / Monitoring of patients on mechanical ventilation

Las manifestaciones de un paciente en insuficiencia respiratoria aguda reflejan el nivel de dependencia, los cuidados que necesita y el soporte ventilatorio mecánico que precisa. Los objetivos de la ventilación mecánica (VM) son corregir la hipoventilación, mejorar la oxigenación y el transporte de oxígeno, y disminuir el trabajo respiratorio. Los cuidados de enfermería que requiere un paciente conectado a VM varían en función de su estado y del modo de ventilación empleado. Cuando una enfermera responsable de un paciente en VM establece un plan de cuidados, identifica los objetivos útiles como instrumento de medida para evaluar constantemente las intervenciones. La monitorización del soporte ventilatorio se incluye dentro de las intervenciones y se encamina a constatar que los objetivos se consiguen. En este artículo se revisan los ítems que nos permiten la monitorización del paciente ventilado desglosada en monitorización general y monitorización respiratoria. (AU)

Prognostic significance of DNA ploidy, S-phase fraction, and tissue levels of aspartic, cysteine, and serine proteases in operable gastric carcinoma.

A consecutive series of 63 untreated patients undergoing surgical resection for stage I-IV gastric adenocarcinomas (GCs) has been prospectively studied. Our purpose was to analyze the predictive relevance of DNA ploidy, S-phase fraction (SPF), and tissue levels of lysosomal proteinases cathepsin D (CD), cathepsin B (CB), cathepsin L (CL), and urokinase-type plasminogen activator (uPA) and that of the intracellular cysteine proteinase inhibitor stefin A on clinical outcome. All of the patients taking part in this study were followed up for a median of 73 months. DNA aneuploidy was present in 71% of the cases (45/63), whereas 9% of these (4/45) showed multiclonality. Both DNA ploidy and SPF were associated with tumor-node-metastasis (TNM) stage and node status, whereas only DNA ploidy was related to depth of invasion. CB, CL, uPA, but not CD, levels were significantly higher in GC as compared to paired normal mucosa, whereas stefin A levels were lower in tumor tissues. CB levels were significantly associated with TNM stage, nodal status, histological grade, and DNA ploidy. At univariate analysis, only node involvement, advanced TNM stage, DNA aneuploidy, and high SPF proved to be significantly related to quicker relapse and to shorter overall survival, whereas depth of invasion was related only to survival. With multivariate analysis, only high SPF (>15.2%) was related to risk of relapse (RR = 8.50), whereas high SPF and DNA aneuploidy were independently related to risk of death (RR = 1.88 and 2.09, respectively). Our preliminary prospective study has identified SPF and DNA ploidy as important biological indicators for predicting the outcome of patients with GC.

Modalidades de ventilación mecánica / Modalities of mechanical ventilation

El empleo de la ventilación mecánica (VM) permite mejorar los síntomas y reducir las complicaciones de la insuficiencia respiratoria aguda (IRA). Los recientes avances en la tecnología de los microprocesadores han incrementado la sofisticación de los ventiladores mecánicos, hecho que ha comportado la aparición de nuevas modalidades ventilatorias. Este artículo tiene como objetivo la descripción de las modalidades ventilatorias disponibles, agrupadas en modalidades convencionales, modalidades alternativas y nuevas modalidades. En las convencionales, se describen aquellas que son más ampliamente empleadas; en las alternativas, aquellas cuyo uso es menos habitual, y en nuevas modalidades se incluyen las que han sido recientemente introducidas y están disponibles en los ventiladores mecánicos de última generación. (AU)

[Monitoring patients on mechanical ventilation]. / Monitorización del paciente en ventilación mecánica.

The clinical situation of a patient with acute respiratory failure, indicates the level of care and mechanical ventilatory support required. The aims of mechanical ventilation are to correct hypoventilation, improve oxygenation and oxygen transport and reduce the work of breathing. Nursing care of patients under mechanical ventilation varies according to their state and the ventilation mode. When establishing a care plan, nurses identify the objectives, which will be useful to measure the interventions. These interventions include aspects related to monitoring and indicate whether or not the objectives are met. In this article the items that allow monitoring of a patient under mechanical ventilation grouped into general monitoring and respiratory monitoring are reviewed.

[Intra-arterial chemotherapy in the treatment of liver metastases of colorectal cancer]. / La chemioterapia intrarteriosa nel trattamento delle metastasi epatiche da cancro del colon-retto.

AIM: The authors evaluate the value of hepatic intrarterial chemotherapy (HAC) as an alternative treatment for hepatic metastases from colo-rectum cancer unsuited to radical surgery. METHODS: This study evaluates the physiopathological and pharmacodynamic bases for this type of treatment, the correct procedure for patient staging and selection, the surgical technique used to insert the infusional system, surgical complications and those linked to endoarterial treatment, the evaluation of response and the results. Complications correlated to the infusional system were evaluated in a total of 1223 patients in 10 non-randomised studies and 7 randomised studies taken from the literature. Complications correlated to chemotherapy were analysed in a total of 777 patients from 8 randomised studies and 7 randomised using FUDR. Special emphasis was placed on the possible association of locoregional and systemic treatment in order to prevent extrahepatic progression, the main cause of death in patients undergoing a single cycle of HAC. RESULTS: By comparing locoregional and systemic treatment taken from a number of randomised and non-randomised studies, the results were evaluated in terms of objective response and survival. CONCLUSIONS: There was no proportional increase in survival rates compared to systemic treatment only, in spite of the large proportion of objective responses achieved using locoregional treatment alone.

Prognostic significance of proliferative activity, DNA-ploidy, p53 and Ki-ras point mutations in colorectal liver metastases.

Paired colorectal liver metastases (CLM) and normal tissue samples from a consecutive series of 36 patients were studied prospectively. MIB-1 expression was studied by immunohistochemistry on paraffin-embedded sections. DNA ploidy and S-phase fraction (SPF) measurements were performed by flow cytometry on frozen tissues. Mutations within the p53 (exons 5-8) and c-Ki-ras (codons 12 and 13) genes were detected by PCR single-strand conformation polymorphism analysis followed by sequencing. A high correlation was observed between the MIB-1 LI and SPF value (rho=0.81; P<0.01). Moreover, p53 gene mutations were associated with either high MIB-1 LI and high SPF. In univariate analysis, SPF and MIB-1 levels were related to risk of death. The association between overall survival and DNA-ploidy or p53 mutations did not reach statistical significance, but a slightly better survival was observed for patients either with DNA-diploid tumours or without mutations (P=0.05 and P=0.06, respectively). SPF was shown by multivariate Cox model analysis to be an independent prognostic variable and thus it might be a useful prognostic factor in patients with CLM.

ras and myc analysis in primary and metastatic colorectal carcinomas.

Paired primary colorectal adenocarcinoma and normal frozen tissue samples from 60 patients were prospectively studied to determine the frequency of point mutations in K-ras and the occurrence of structural alterations in c-myc. Parallel investigations were performed on liver metastatic specimens from 16 of the patients. 47% of the primary tumors presented point mutations in K-ras; 71% of these were in codon 12. Significant associations were found between codon 13 ras mutations and Dukes' D stage (p<0.05), and between mutations in codon 12 and mucinous type (p<0.01). The c-myc gene structure was altered in 5/60 cases (8%). In 4/16 cases, the K-ras gene status in the primary carcinoma and in the metastatic tissue from the same patient was found to be different. Our results suggest that codon 13 I-as mutations may be associated with an increased invasive and metastatic potential, while codon 12 mutations may have a role in the mucinous differentiation pathway.

Induction of parturition in alpacas and subsequent survival of neonates.

OBJECTIVE: To evaluate use of fluprostenol, dexamethasone, and oxytocin for induction of parturition in alpacas, and to determine viability of the newborn crias. DESIGN: Prospective, randomized, controlled trial. ANIMALS: 36 pregnant alpacas within 10 days of parturition. PROCEDURE: Animals were randomly assigned to treatment groups. Plasma progesterone and plasma and urine estrone sulfate concentrations were measured for 5 days after treatment. Clinical signs of the neonates were determined. RESULTS: Time between treatment and parturition was significantly shorter for animals that received fluprostenol than for animals in any other group. The highest dose of dexamethasone (0.5 mg) caused fetal death. None of the other treatments induced early parturition. Time between birth and first suckling, body weight, rectal temperature, pulse rate, and respiratory rate at birth and serum IgG concentration 24 hours after birth were not different between crias born after fluprostenol treatment and crias born to control alpacas. CLINICAL IMPLICATIONS: Fluprostenol was effective at inducing parturition in these alpacas, but dexamethasone and oxytocin were not. Crias born after fluprostenol treatment were similar to crias born to control alpacas.

nm23-H1 protein immunohistochemical expression in human breast cancer.

A series of 76 patients undergoing surgery for primary breast carcinoma has been prospectively studied in order to evaluate the relative weight of nm23-H1 protein expression in disease-free survival. Expression of nm23 protein was immunohistochemically assessed. In all, 39% (29/74) of the turners showed positive staining for nm23-H1 protein expression. Negative nm23-H1 expression was found in poorly differentiated, tumors (p<0.02). There was no significant relationship between nm23-H1 and the other clinicopathological and biological features examined. In the univariate statistical analysis, node positivity, G3 histological grade and high flow cytometric S phase fraction (SPF) value proved to be significantly related to risk of relapse. In the multivariate analysis, only histological grade (G3) and high SPF values (>10.6) proved to be independently related to risk of relapse, with a hazard ratio of 9.84 and 7.98 respectively. Our preliminary study suggests that immunohistochemical nm23-H1 expression should not be considered a marker for predicting tumor progression and patient prognosis.

Vimentin expression, proliferating cell nuclear antigen and flow cytometric factors. Prognostic role in breast cancer.

A series of 71 patients undergoing surgery for primary breast carcinoma was prospectively studied in order to evaluate the relative weight for four biologic factors (intermediate filament vimentin expression, proliferating cell nuclear antigen [PCNA], flow cytometric DNA ploidy and S-phase fraction) and of several clinicopathologic and biologic features in predicting clinical outcome (disease-free interval). In univariate statistical analysis, positivity of axillary nodes, high number of mitoses, high nuclear grade, high histologic grade, positivity of vimentin, high flow cytometric S-phase fraction (FCM-S) value, high PCNA and high silver-stained nuclear organizer regions scores were significantly related to risk of relapse. In multivariate analysis (Cox's logistic regression) only histologic grade (3) and high FCM-S values (> 10.7) were independently related to risk of relapse, with hazard ratios of 9.84 and 7.98, respectively. The results of our preliminary, prospective study suggest that FCM-S, in addition to morphologic criteria (histologic grade), may be an important biologic indicator in determining breast cancer patients' prognosis.

Structural analysis of c-myc in human sporadic colorectal carcinomas.

Analysis of the DNA extracted from the colonic mucosa of 13 patients operated for colorectal carcinoma revealed c-myc rearrangements in three of them. In all cases, the alterations were found both in the histologically normal and in the tumoral mucosa. In one case, a different pattern of rearrangements characterized the two tissues. In all three individuals, the c-myc sequences appeared to be amplified. We suggest that c-myc rearrangements in the histologically normal colonic mucosa of colorectal carcinoma patients could represent a predisposition factor for the development of additional neoplasms.

Immunocytochemical determination of estrogen and progesterone receptors and flow cytometric DNA analysis of breast cancer on fine needle aspirates.

A prospective study was performed on a series of 42 patients with breast carcinoma. Immunocytochemical determination of receptors for estrogens (ER) and progesterone (PR) and flow cytometric DNA analysis (DNA-ploidy and the S-phase fraction) were performed on material obtained from fine-needle aspirates (FNA). The patients underwent subsequent surgery, and the same parameters were determined on the surgical samples. The correlation between the biochemical and the immunocytochemical methods gave for ER, r = 0.853, p < 10 (-6) and for PR, r = 0.830, p < 1.6 (-6). In addition, comparisons of FNA's with the surgical samples showed significant relationships for the DNA index (r = 0.96, p < 0.000001) and for the S-phase fraction (r = 0.88, p < 0.000001).