Chemical characterization (LC-MS-ESI), cytotoxic activity and intracellular localization of PAMAM G4 in leukemia cells.

Generation 4 of polyamidoamine dendrimer (G4-PAMAM) has several biological effects due to its tridimensional globular structure, repetitive branched amides, tertiary amines, and amino-terminal subunit groups liked to a common core. G4-PAMAM is cytotoxic due to its positive charges. However, its cytotoxicity could increase in cancer cells due to the excessive intracellular negative charges in these cells. Furthermore, this work reports G4-PAMAM chemical structural characterization using UHPLC-QTOF-MS/MS (LC-MS) by electrospray ionization to measure its population according to its positive charges. Additionally, the antiproliferative effects and intracellular localization were explored in the HMC-1 and K-562 cell lines by confocal microscopy. The LC-MS results show that G4-PAMAM generated multivalent mass spectrum values, and its protonated terminal amino groups produced numerous positive charges, which allowed us to determine its exact mass despite having a high molecular weight. Additionally, G4-PAMAM showed antiproliferative activity in the HMC-1 tumor cell line after 24 h (IC50 = 16.97 µM), 48 h (IC50 = 7.02 µM) and 72 h (IC50 = 5.98 µM) and in the K-562 cell line after 24 h (IC50 = 15.14 µM), 48 h (IC50 = 14.18 µM) and 72 h (IC50 = 9.91 µM). Finally, our results showed that the G4-PAMAM dendrimers were located in the cytoplasm and nucleus in both tumor cell lines studied.

Immunoneuroendocrine alterations in patients with progressive forms of chronic Chagas disease.

We studied the features of parallel immunoneuroendocrine responses in patients with different degrees of chronic Chagas myocarditis (indeterminate, mild/moderate or severe). A systemic inflammatory scenario was evident in patients with severe myocarditis compared to healthy subjects. This was paralleled by a disrupted activation of the hypothalamus-pituitary-adrenal axis, characterized by decreased concentrations of dehydroepiandrosterone-sulfate (DHEA-s) and an unbalanced cortisol/DHEA-s ratio, reinforcing the view that severe Chagas disease is devoid of an adequate anti-inflammatory milieu, likely involved in pathology. Our study constitutes the first demonstration of neuroendocrine disturbances, in parallel to a systemic inflammatory profile, during progressive human Chagas disease.

Short treatment with the tumour necrosis factor-alpha blocker infliximab diminishes chronic chagasic myocarditis in rats without evidence of Trypanosoma cruzi reactivation.

Tumour necrosis factor (TNF)-alpha is crucial for resistance to Trypanosoma cruzi acute infection, but there is scant information on its role during the chronic phase. To address this issue, we analysed whether a short treatment with a TNF-alpha blocker affected the course and characteristics of chronic disease in a rat experimental model of T. cruzi infection. An anti-TNF-alpha agent (infliximab) was administered during the chronic phase for a period of 4 weeks (3 mg/kg/week), while control infected rats were inoculated with saline physiological solution. Search for parasites yielded non-successful results in all infected groups, irrespective of treatment. Nevertheless, the presence of T. cruzi kDNA in heart tissue was detected in infected and infected plus treated animals. Because infliximab might induce changes in the anti-parasite cytokine response, circulating levels of interleukin (IL)-10, interferon-gamma and nitric oxide were evaluated. An increase in IL-10 levels was observed only in the infected group treated with the anti-TNF-alpha blocker compared to the remaining groups (P < 0.05). A clear attenuation of histological damage associated with a diminution of cardiac TNF-alpha mRNA expression was observed in the infected and treated animals compared to the infected and non-treated group. Blocking of TNF-alpha during a relatively short period in chronically infected rats did not lead to evident parasite reactivation but reduced myocarditis severity significantly, indicating a role of this cytokine in the pathogenesis of chronic myocardial damage.

Deficient control of Trypanosoma cruzi infection in C57BL/6 mice is related to a delayed specific IgG response and increased macrophage production of pro-inflammatory cytokines.

Earlier work in Trypanosoma cruzi-infected C57BL/6 and BALB/c mice revealed an acute disease, of lethal outcome in the former group and lesser severity in BALB/c mice. Fatal course was not accompanied by an increased parasite load, but by a substantial imbalance between pro- and anti-inflammatory cytokine serum levels. To better characterise the mechanisms allowing the host to restrain the infection, we have now studied the specific IgG production and in vitro behaviour of peritoneal macrophages (PMs) when exposed to T. cruzi. BALC/c mice displayed higher serum levels of specific immunoglobulins in the first weeks of acute infection. In vitro infected PMs showed no between-group differences in the number of intracellular parasites, although TNFalpha levels were significantly higher in culture supernatants from C57BL/6 mice. Because an LPS-based pretreatment (desensitisation protocol followed by a sublethal LPS dose) reduced disease severity of C57BL/6 mice, we next explored the features of the in vitro infection in PMs from mice subjected to such protocol. PMs from LPS-pretreated mice had a decreased production of TNFalpha and IL-1beta, becoming more permissive to parasite replication. It is concluded that deficient control of T. cruzi infection in C57BL/6 mice may also involve a less satisfactory specific IgG response and increased TNFalpha production by PMs. Improved disease outcome in LPS-pretreated mice may be associated with the reduced inflammatory cytokine production by PMs, but the impaired ability of these cells to control parasite growth suggests that compensatory mechanisms are operating in the in vivo situation.

Obesity adversely affects the outcome of antireflux operations.

BACKGROUND: We hypothesized that obesity was associated with long-term failure of antireflux procedures, and that in obese patients antireflux operations were easier to perform via thoracotomy, and therefore likely to have a higher success rate than transabdominal (laparoscopic or open) antireflux procedures. The aims of this study was to determine the impact of obesity on the success of antireflux operations, and to compare the success rates of transthoracic and laparoscopic approaches in obese patients with gastroesophageal reflux. METHODS: The records of 224 consecutive patients undergoing antireflux surgery by two surgeons in a university-based tertiary care center were reviewed and patients contacted for follow-up assessment. The patients were classified into groups based on the type of operation performed and the calculated body mass index (BMI): normal (BMI 30). Recurrences were documented by symptoms responsive to acid-suppressive medication and radiologic or pH probe studies. RESULTS: Among the 224 patients included in this study, 187 underwent laparoscopic Nissen fundoplications (LNF) and 37 underwent Belsey Mark IV(BM4) procedures. The mean follow-up period was 37 months. The three groups included 89 (39.7%) patients classified as having normal weight, 87 (38.8%) as overweight and 48 (21.4%) as obese. Normal, overweight, and obese patients were similar in terms of age, gender, hiatal hernia size, degree of esophagitis, and comorbid conditions. A total of 26 recurrences occurred, giving an overall recurrence rate of 11.6%. There were 4 recurrences in the normal group (4.5%), 7 in the overweight group (8.0%; p not significant vs normal), and 15 in the obese group (31%; p < 0.001 vs normal; p <.001 vs overweight). The recurrence rate was similar between LNF and BM4 in each BMI subgroup, although in aggregate, the recurrence rate after BMW was greater than after LNF (10/37 vs 16/187; p < 0.02). CONCLUSIONS: Obesity adversely affects the long-term success of antireflux operations. Although athoracotomy provides optimal exposure of the hiatal structures in obese patients, a transthoracic approach was associated with a higher recurrence rate than LNF. Given the high failure rate of antireflux operations in obese patients, intensive efforts at sustained weight loss should be made before consideration of surgery.

[Helicobacter pylori infection in a group of HIV/AIDS patients]. / Infección por Helicobacter pylori en un grupo de pacientes VIH/SIDA.

The prevalence of H. pylori infection in AIDS patients has been controversial. A. controlled prospective and descriptive study was conducted in a group of 64 HIV-infested patients. H. pylori detection was carried out by endoscopic study during which two biopsy samples of gastric antrum and body were taken for the histologic study and other 2 samples of gastric antrum and body for urease testing. H.pylori infection prevalence was 56.3%. The comparison group was composed by 110 serologically HIV-negative patients, with an infection prevalence rate of 77.2%. In the HIV-AIDS group, the frequency of gastric ulcer was 1,5% and no duodenal ulcer was found whereas the comparison group showed a frequency of gastric and duodenal ulcers of 1.8 and 15.5% respectively. HIV+/AIDS patients in category I exhibited an H. pylori infection prevalence of 68.7%, category II, 39.2% and category III, 21,0%. A reversed association was observed between the level of immune deterioration and the prevalence of H. pylori infection.

[Rectal catheter decompression in colonic pseudoobstruction (Ogilvie syndrome). Report of a case and review of the literature]. / Descompresión con sonda rectal en la pseudoobstrucción colónica (síndrome de Ogilvie). Informe de un caso y revisión de la literatura.

The Ogilvie's Syndrome is a major surgical complication. It is defined as a severe dilatation of the colon, the cecum, ascendant and transverse, without the presence air at the distal colon following abdominal surgery. The causes are unknown. We described a clinical case of patient delivered by C-S who developed this syndrome and a review of the literature. We emphasized on the importance of the early diagnosis by the use of the traditional abdomen X-Rays and we described a relatively new approach for this patients through the decompression by colonoscopy using a Levin's catheter successfully. This is an alternative minimum-invasive treatment which could be of a great benefit for the patients with this disease.

The large window ductus: a surgical trap.

A rare window type of patent ductus arteriosus is reported that was large (15 mm in maximal transverse dimension) but had virtually no length and hence was externally invisible. The smaller aortic isthmus (4 mm in diameter), which was intrapericardial, was mistaken for the ductus and was inadvertently clip-occluded, leading to death. After a specific diagnosis is made, the large window ductus should be patched on cardiopulmonary bypass with a transpulmonary approach.

Estudio de la inmunidad celular in situ en eritema discrómico perstans y vitiligo / Study in situ of the cellular immunity in erythema dyschromicum perstans and vitiligo

El Eritema Discrómico Perstans (EDP) y el Vitiligo son dos dermatosis pigmentarias cutáneas de etiología desconocida. En el presente estudio los infiltrados leucocitarios de EDP (n=10) y de Vitiligo (n=5) fueron estudiados, usando la técnica de la inmunoperoxidasa de avidinabiotina (ABC) y anticuerpos monoclonales que reconocen las siguientes subpoblaciones celulares: T-Supresor-Citotóxico (CD8=Leu-2), T-cooperadores (CD4=OKT4), T-Supresores (Leu-15), Pan T (Leu-4), Macrófagos (Leu-M3) y células de Langerhans (CD1=Leu-6); y marcadores celulares para antígeno la, Gamma Interferón, Interleucina-2 y receptor para Interleucina-2. El análisis inmunocitoquímico mostró una acumulación selectiva de células T-Citotóxicas Leu-4+, Leu-2+, Leu-15-en la epidermis tanto de EDP como de lesiones recientes de Vitiligo. Además, un aumento en el número de células de Langerhans epidérmicas Leu-6 se observó en algunos de los casos de EDP y de Vitiligo. La relación CD4/CD8 en las lesiones y en la piel no envuelta para ambos desórdenes no mostró diferencias significativas, no obstante valores menores que uno se apreciaron sólo en los infiltrados de piel lesionada. Los macrófagos en los infiltrados dérmicos de EDP se encontraban generalmente yuxtapuestos al pigmento melánico. Los linfocitos que expresaban en su superficie antígenos tipo TAC, IL-2 y Gamma Interferón, fueron muy pocas en los infiltrados dérmicos. Algunas células NK se encontraban también presentes en la epidermis enferma. Estas observaciones morfológicas sugieren una importante participación de la inmunidad celular en la discromia de diversos desórdenes pigmentarios cutáneos

Antibodies against animal growth hormones appearing in patients treated with human growth hormone: their specificities and influence on growth velocity.

The appearance of anti-human growth hormone (hGH) and anti-non-hGHs antibodies in 27 patients with idiopathic hypopituitarism, treated for periods of 6-18 months with three different preparations of hGH, was investigated. The preparations induced antibodies to GH in 21 out of the 27 patients: 10 patients produced exclusively an anti-non-hGH response, whereas 11 generated both anti-non-hGH and anti-hGH antibodies. The levels of antibodies against hGH had low correlation with decreased growth velocity, whereas those for the antibodies against non-hGHs did not correlate with decreased growth velocity.

Human, bovine, and equine growth hormone antibodies in patients treated with human growth hormone.

The immunological behavior of sera from hypopituitary patients treated with human GH (hGH) has been studied by homologous and heterologous RIAs using 125I-labeled hormones. Along with antibodies against hGH, antibodies exhibiting antibovine and antiequine GH (anti-bGH and anti-eGH, respectively) activities were also found. Displacement experiments showed that hGH was an effective competitor of 125 I-labeled hGH, whereas bGH and eGH were quite inefficient. Conversely, when the tracer was 125I-labeled bGH, both bGH and eGH were good displacers, while the human hormone was poor. The values of the affinity constants of the various antibodies found in human sera were similar to each other and to those found after immunization of rabbits. These results suggest that the antibodies against bGH and eGH belong to a population separate from those directed against the human hormone. The mechanism by which hGH can express determinants of other animal growth hormones is obscure, although the high degree of conservation of structure in these molecules during evolution must be involved.