Site-Selective TiO2 Coating on Asymmetric Patchy Particles.

The successful fabrication of TiO2-faced asymmetric patchy particles consisting of polystyrene and a Fe3O4/SiO2/TiO2 part is described. Such particles can be of large interest for photochemistry. The used site-selective coating approach demonstrates a modification strategy for a special patchy particle family which may have a general character. The stability of the coating has been tested under several conditions with no sign of disruption. The influence of the prepared asymmetric particles on oil/water phase mixing behavior was tested and turned out to be very diverse. Oils with low polarity (e.g., hexadecane, cyclohexane, octadecane) can form Pickering emulsions by the help of these particles; oils with high polarity (e.g., 1-octanol) form monodisperse macrodroplet systems with unusual stability.

Amphiphilic Pickering Emulsifiers Based on Mushroom-Type Janus Particles.

Iron-based mushroom-type Janus particles consisting of a poly(sytrene-co-divinylbenzene) and a silica moiety both with controllable morphologies were successfully synthesized on the gram scale and investigated as surfactants for Pickering emulsions. Two oil-water model systems, namely toluene-water and vegetable oil-water, were stabilized, giving mainly water-in-oil (w/o) emulsions. By varying several parameters, including Janus particle morphologies and the oil-water ratio, fine-tuning of the emulsion systems was possible; it was even possible to invert the continuous phase to an oil-in-water (o/w) system. Furthermore, the emulsions were stable against coalescence and sedimentation and could be easily separated by centrifugation or a strong magnet. The synthesized mushroom-type Janus particles are suitable for creating Pickering emulsions and can be used as building blocks for creating nanostructures with tailored properties for specific applications.

Pediatric renal transplantation: 13 years of experience--report from the Chilean Cooperative Multicenter Group.

Between 1989 and 2002, 178 renal transplants were performed in 168 pediatric patients in Chile. The mean age was 10.9 +/- 3.7 years (range 1 to 17.9). End-state renal disease etiologies were: congenital renal hypoplasia/dysplasia, chronic glomerulonephritis, and reflux nephropathy. Seventy received a graft from a living donor (LD), and 108 from a cadaveric donor (CD). Only 9% received antibody induction. Acute rejection episodes were reported in 76 patients: 38% in LD recipients and 48% in CD recipients (P = NS). One-, 3-, and 5-year graft survivals were 88%, 84%, and 76%, respectively, for LD and 86%, 79%, and 68% for CD recipients. Actuarial graft survival was significantly better among those patients with serum creatinine < 1 mg/dL at 1 year posttransplant compared with those with creatinine > 1 mg/dL (P < .05). The graft survival rate has improved from the first period (1989 to 1996) to the second period (1997 to 2002); (P = .05). Patient survival rates at 1, 3, and 5 years were 98%, 98%, and 98%, respectively, for LD, and 95%, 94%, and 94% for CD. Global height/age Z-score decreased from -0.7 at birth to -1.5 when dialysis started, and to -2.4 at the time of transplantation. The Z-score height/age at 1, 3, and 5 years posttransplantation was -2.25, -2.24, and -2.5. No significant differences were observed in transplant outcomes comparing patients younger than 7 years with those older ones. In conclusion, pediatric renal transplant has been performed in Chile with acceptable morbidity. The patient and graft survivals are similar to the reported international experience. In the last period there was a significant improvement in graft survival.

Basiliximab: efficacy and tolerability in adults and children.

UNLABELLED: An open, single arm, prospective clinical trial to assess the efficacy and safety of basiliximab (Simulect) combined with cyclosporine microemulsion (Neoral), steroids, and azathioprine was performed in four centers in Chile, two adult and two pediatric. The 23 patients who were enrolled were followed for 12 months. There were four acute rejection episodes (three adults and one child) and three graft losses (two adults and one child) during the study. Renal function in both adult and pediatric patients at 6 and 12 months was good. Basiliximab was well tolerated. The incidence of infections was low, with only one CMV infection. There were no deaths. CONCLUSIONS: The incidence of acute rejection episodes among renal allograft recipients treated with basiliximab is low, showing that the drug is well tolerated. In particular the number of CMV infections is extremely low.

[Renal scintigraphy with Tc99m DMSA (dimercaptosuccinic acid) in acute pyelonephritis]. / Cintigrafía renal con Tc99m DMSA (acido dimercaptosuccínico) en pielonefritis aguda.

Twenty patients, 6 months to 11 year old, with clinically recognized acute pyelonephritis, were evaluated with Tc99m DMSA renal scintigraphy in the first 15 days of their illness to validate this method in the detection of the acute renal inflammatory disease. In 85% of Tc99m DMSA scintigraphies some kind of abnormality (focal or diffuse, unilateral or bilateral) was observed. Second renal images obtained at an average 8.5 months later, showed total disappearance of abnormal findings in 42%; partial regression in 50% and no changes in 8% of these cases. Tc99m DMSA scintigraphy seems to be a good diagnostic tool to confirm acute renal compromise in urinary tract infections. Besides follow up examinations, at least three months later with this same method, were able to confirm sustained renal lesions.

[Neonatal bacterial infections: magnitude and clinical aspects]. / Infecciones bacterianas neonatales: magnitud y aspectos clínicos.

A prospective study on major bacterial infections (MBI) has been made over a six-month period in a neonatal unit. Incidence of MBI was 6.8 per 1,000 live births. Rates were significantly higher in low (57/1,000) and very low-birth-weight newborns (200/1,000). Septicemia occurred most frequently with group B hemolyticus streptococcus and staphylococcus aureus as the commonest infecting organisms. In 19/33 haematologic studies abnormal neutrophilic cell counts, thrombocytopenia or both were seen. Case/fatality rate was 50% in this series.

[Initial therapy of primary nephrotic syndrome in children: evaluation in a period of 18 months of two prednisone treatment schedules. Chilean Co-operative Group of Study of Nephrotic Syndrome in Children]. / Cuadro inicial del sindrome nefrósico primario del niño: evaluación a 18 meses de dos esquemas de tratamiento con prednisona. Groupo Cooperativo Chileno de Estudio del Sindrome Nefrósico del Niño.

Ninety six patients aged from 6 months to 15 years and were admitted to Chilean hospitals with the diagnosis of primary nephrotic syndrome in a period of 30 months. These patients were randomly separated in two groups, group A received prednisone for 8 weeks and group B received the same drug during 12 weeks. All patients were evaluated at 6, 12 and 18 months after the end of treatment. The moment and number of relapses per patient, accumulated percentage of relapses, relapse rate per 100 patients, total number of relapses and complications were assessed. Frequent relapsers were subjected to a kidney biopsy, leaving in the protocol only those patients that had minimal changes. Patients resistant or dependent to steroid therapy were discarded. Thus we report the results of 56 treated patients followed during 18 months. No differences in analyzed parameters were observed between the two treatment groups. It is concluded that these preliminary results do not support the prolongation of prednisone treatment in children with primary nephrotic syndrome.

[Sexuality in adolescents]. / Sexualidad en adolescentes.

PIP: A survey of knowledge, attitude, and practices regarding human reproduction and sexuality was undertaken in 2 groups of secondary school students in Chile to assess whether greater knowledge of reproduction and sexuality is associated with greater permissiveness and earlier initiation of sexual activity. Students in 2 public schools, 1 coeducational and 1 for female students only, were of lower middle class background, while students at the coeducational private school were of higher socioeconomic status. An anonymous, semiclosed questionnaire was administered to students in the 3 schools. The schools were selected because their directors agreed to permit the study. 14.8% of the 351 public school students were aged 14 or under and 77.8% were 15-18, while 99.5% of the 197 private school students were aged 15-18. The students' levels of knowledge of human reproduction and sexuality were measured through direct personal assessments by the students themselves and through 21 questions to confirm the assessments. At least 93% of students in all schools said their level of knowledge was medium or high, but the test indicated that only 64% of public school students and 75% of private school students actually had medium or high levels of knowledge. 45.9% of private and 27.9% of public school students felt the information they received from their schools about sexuality was adequate, while 41.9% of private and 60.9% of public school students felt it was insufficient. There were no significant differences in the opinions of the 2 groups of students concerning premarital sex, but the reasons given by the private school students to explain their attitudes expressed a greater sense of commitment to the partner, while those of the public school students tended to be more functional. Among public school students, 38.7% of males and 9.7% of females reported having had sexual relations, while among private school students, 17.7% of males and 4.4% of females reported having done so. No significant differences were reported in the age of initiating sexual activity in the 2 groups. Students in the school with the highest overall level of knowledge of human reproduction and sexuality had lower overall levels of sexual activity.^ieng

[Lawsuits against physicians in Chile]. / Demandas judiciales contra médicos en Chile.

Lawsuits against are becoming relevant in Chile. We analyzed 18 trials against physicians that occurred between 1977 and 1985 and that were ruled by Metropolitan Region courts. The causes of demands were death of patients in 8 trials and severe lesions in the rest. Twelve trials originated from surgical procedures (six from gynecological interventions), and nine came from private clinics. Nine trials lasted less than two years and three, more than 5 years. Sentence was pronounced by criminal courts in 12 cases and by appealing courts in six.

[Renal artery thrombosis in newborn infants undergoing umbilical artery catheterization]. / Trombosis de arteria renal en recién nacidos sometidos a cateterización de la arteria umbilical.

A prospective study to detect renal artery thrombosis by radionuclide renal scintigraphy in newborn infants who underwent umbilical arterial catheterization over a one year period was done: 62 babies were catheterized, 92% were preterm and 85% had severe respiratory distress syndrome that required mechanical ventilation, 25/62 (40.3%) survived and in all of them Tc-99m DMSA scans were taken at a median of 5 days after withdrawal of the umbilical artery catheters (range 9 h to 29 days). A baby with renovascular hypertension had a DMSA scan which showed segmental vascular defect in one kidney. Another patient had left iliac artery thrombosis and two others showed evidence of transient vasospasm. Death occurred in 37/62 (59.7%), 92% of whom underwent autopsy studies which showed aortoiliac thrombosis in 8.8%, all of them without clinical symptoms. Other 12 newborn infants who died without previous umbilical artery catheterization had no evidence of thrombosis at autopsy.

Complicaciones de la prostatectomía radical retropúbica: nuestra experiencia / Complications of retropubic radical prstatectomy: our experience

Entre mayo de 1992 y febrero de 1995, 33 pacientes con cáncer prostático clínicamente localizados fueron sometidos a linfadenectomía ilíaca y prostatectomía radical retropúbica en el Departamento de Urología del Hospital San Juan de Dios. Dentro de las complicaciones tempranas destaca la filtración por drenaje mayor a 5 días se presentó en 12,2 por ciento de los casos. La importancia se demostró en 69,9 por ciento e incontinencia total en 1 caso (3 por ciento). No hubo mortalidad intraoperatoria ni en el postoperatorio inmediato