Real-time monitoring of plasmon induced dissociative electron transfer to the potential DNA radiosensitizer 8-bromoadenine.

The excitation of localized surface plasmons in noble metal nanoparticles (NPs) results in different nanoscale effects such as electric field enhancement, the generation of hot electrons and a temperature increase close to the NP surface. These effects are typically exploited in diverse fields such as surface-enhanced Raman scattering (SERS), NP catalysis and photothermal therapy (PTT). Halogenated nucleobases are applied as radiosensitizers in conventional radiation cancer therapy due to their high reactivity towards secondary electrons. Here, we use SERS to study the transformation of 8-bromoadenine (8BrA) into adenine on the surface of Au and AgNPs upon irradiation with a low-power continuous wave laser at 532, 633 and 785 nm, respectively. The dissociation of 8BrA is ascribed to a hot-electron transfer reaction and the underlying kinetics are carefully explored. The reaction proceeds within seconds or even milliseconds. Similar dissociation reactions might also occur with other electrophilic molecules, which must be considered in the interpretation of respective SERS spectra. Furthermore, we suggest that hot-electron transfer induced dissociation of radiosensitizers such as 8BrA can be applied in the future in PTT to enhance the damage of tumor tissue upon irradiation.

Estradiol and drospirenone for climacteric symptoms in postmenopausal women: a double-blind, randomized, placebo-controlled study of the safety and efficacy of three dose regimens.

METHOD: A randomized, placebo-controlled trial was conducted to evaluate the safety and efficacy of drospirenone (1, 2 or 3 mg) combined with estradiol (1 mg) in the treatment of climacteric symptoms in healthy postmenopausal women. RESULTS: The frequency of hot flushes was significantly decreased in all treatment groups (range 86-90%) in comparison to placebo (45%, p < or = 0.001) and remained suppressed at 16 weeks. Treatment with drospirenone and estradiol also decreased the intensity and severity of sweating, sleep problems, depression, nervousness, and urogenital symptoms. Most adverse events were mild or moderate, with similar rates observed in all groups. No serious adverse events or clinically significant laboratory abnormalities attributed to treatment occurred. CONCLUSION: These results demonstrate that the combinations of 1, 2, and 3 mg drospirenone with 1 mg estradiol are safe and effective for the treatment of climacteric symptoms.

Ultrasound in the investigation of tubal patency. A meta-analysis of three comparative studies of Echovist-200 including 1007 women.

DESIGN: This study is a meta-analysis of the results of three clinical studies of the ultrasound echo-contrast agent Echovist-200 with transvaginal contrast sonography (HyCoSy) in the demonstration of tubal patency. Results from 1007 patients were included in the analysis, of whom 986 patients were examined for tubal patency. The HyCoSy findings were compared with those of chromolaparoscopy in 428 cases and with those of hysterosalpingography (HSG) in 202. RESULTS: The results of HyCoSy and chromolaparoscopy were identical in 294 of 428 patients (68.7%) or in 688 of 828 individual tubes (83.1%). HyCoSy showed "false" occlusion in 85 tubes (10.3%) and "false" patency in 55 (6.7%). The results of HyCoSy and HSG were identical in 138 of 202 patients (68.3%) or in 320 of 384 individual tubes (83.3%). HyCoSy showed "false" occlusion in 49 tubes (12.8%) and "false" patency in 15 (3.9%). The findings of chromolaparoscopy and HSG agreed in 49 of 77 patients (63.6%) or in 116 of 152 tubes (76.3%). HSG showed "false" occlusion in 19 (12.5%) tubes and "false" patency in 17 (11.2%). TOLERANCE: Echovist-200 was well tolerated. The most frequent adverse event was pain, which was mild in 42.3% of patients and severe in 10.1%. Pain was clearly related to tubal occlusion. Other adverse events such as vasovagal reactions or nausea occurred in 7.0% of patients, but the events required treatment in only 1.9%.

Mandibular setback for surgical correction of mandibular hyperplasia--does it provoke sleep-related breathing disorders?

The question has arisen as to whether mandibular setback may possibly cause sleep-related breathing disorders (SRBD). To evaluate the possible effects of mandibular setback on posterior airway space (PAS), 16 consecutive patients were examined prospectively. All patients underwent surgical mandibular setback using bilateral sagittal split osteotomy. Polysomnographic evaluation for SRBD was performed according to the Marburg graded diagnostic protocol before and after surgery. Cephalometric analysis was performed preoperatively, and 1 week, 3 months, and 1 year postoperatively, with particular attention to pharyngeal changes. PAS decreased considerably in all patients. Nevertheless, the preoperative PAS was enlarged in all patients with mandibular hyperplasia compared to normal subjects. Despite the pharyngeal narrowing, there was no evidence of postoperative SRBD in any of these patients. SRBD as a consequence of mandibular setback may be rare; nevertheless, the pharyngeal airway does decrease.

Saccharide-based contrast agents. Characteristics and diagnostic potential.

Since about 1980 tiny bubbles of gas ("microbubbles") have been known to be highly effective in ultrasonography because of enhancing backscatter ultrasound. After about 25 years of experimental work, the first industrial US contrast agent was approved by health authorities, the galactose microparticle SH U 454-Echovist, Schering AG, launched on the German market in 1991. Its major limitation is represented by the fact that it does not pass the pulmonary barrier and is confined to right heart abnormalities. Therefore another agent has been developed, the transpulmonary derivative of Echovist the galactose-based agent with the code number SH U 508 A (Levovist) which is in the late phase of clinical development for cardiac B-mode and Doppler blood pool US enhancement. A wide number of application areas can be foreseen for this contrast agent, which has been used for a multicenter trial. More than 1,200 patients were included in a European phase-III multicenter trial aimed at assessing the diagnostic efficacy and safety of SH U 508 A (Levovist). The patients included in the study had diagnostically insufficient Doppler signal intensity at routine Doppler or color Doppler vascular imaging. In more than 95% of the patients Doppler signal enhancement was achieved with at least one dose at the scheduled regimen, even in peripheral vessels. Enhanced Doppler US allowed a diagnosis to be made in many patients who would have otherwise undergone more invasive procedures. The diagnostic confidence, evaluated on a numerical rating scale (0-100) increased from 25.2 +/- 22.8% (prevalue) to 77.7 +/- 22.2% after Levovist (mean value +/- standard deviation, as calculated for a subgroup of 513 patients). Repeated i.v. injections were well tolerated. No specific risk was found for patients in any disease group.

[Improving diagnosis of blood supply of breast tumors by echo-contrast media]. / Verbesserung der Durchblutungsdiagnostik von Brusttumoren durch Echo-Kontrastmittel.

Doppler blood flow measurements allow differentiation of malignant lesions, that are characterised by an abnormal vascularity. The accuracy of this method is limited due to the physiological flow variation in normal breast parenchyma and in tumours. Magnetic resonance imaging in combination with contrast agents can also be used for flow assessment by measurement of the dynamic contrast enhancement. Recently, a new echo contrast agent (Levovist) has been developed, which survives pulmonary transit and increases the Doppler signal intensity after intravenous injection. Fourteen malignancies with low vascularity were selected for the study. Twenty-two seconds after injection of contrast agent, the Doppler signal intensity increased dramatically. This demonstrates, that echo contrast agents might improve the diagnosis of breast lesions in case of non-conclusive Doppler findings.

Contrast-enhanced transcranial Doppler US with a new transpulmonary echo contrast agent based on saccharide microparticles.

The purpose of this first patient study (phase II) was to evaluate the clinical usefulness of a new echo contrast agent at transcranial Doppler ultrasonography (US). Twenty patients were selected from a group of 242 patients undergoing conventional transcranial Doppler US who had low (n = 18) or absent (n = 2) Doppler signals from the middle cerebral artery (MCA). The extent and duration of Doppler signal increase was measured in 30 MCAs and in 14 basilar arteries following the intravenous injection of a transpulmonary galactose microparticle suspension (SH U 508 A) at three concentrations (200, 300, and 400 mg/mL). Doppler waveform analysis became possible in 93% (28 of 30) of the MCAs following injection. The maximal increase in average Doppler signal intensity (11 dB at 200 mg/mL, 15 dB at 300 mg/mL, and 17 dB at 400 mg/mL) and the increase in average duration of the signal enhancement (163 seconds at 200 mg/mL, 219 seconds at 300 mg/mL, and 240 seconds at 400 mg/mL) depended on contrast agent concentration. Doppler waveform analysis became possible in 79% (11 of 14) of the basilar arteries. The intravenous injection of this new echo contrast agent markedly increases Doppler signal intensity in patients with nondiagnostic results at conventional Doppler US.

[The need for autopsy]. / Sobre la necesidad de la autopsia.

A generalized decrease in the number of autopsies has been observed in hospitals worldwide, including Chile. A significant number of discrepancies between clinical and pathologic diagnosis persists in spite of the increasing sophistication of diagnostic methods. The teaching value of the autopsy, recognized by students, is stressed. Some lessons obtained in the personal practice of over 4500 autopsies are commented upon. The intimate experience of autopsies practiced in relatives and the speculation upon the attitude of the pathologist himself facing an autopsy are discussed.

[Color-coded duplex sonography and ultrasound contrast medium in the study of peripheral arteries--initial clinical experiences]. / Farbkodierte Duplexsonographie und Ultraschallkontrastmittel zur Untersuchung peripherer Arterien--Erste klinische Erfahrungen.

Ultrasound contrast agents (US-CA) amplify reflected sound waves. Most substances used as contrast agents are destroyed when passing the lungs. SH U 508 is a new US-CA that can pass the lungs without impairment after peripheral intravenous application. In a clinical trial of this US-CA, we investigated its effect on the visualization of blood movement in peripheral arteries by color-coded Duplex sonography (CCDS). The leg arteries of 20 patients with severe chronic arterial occlusion were examined by CCDS (QAD I and Platinum) after i.v. application of the US-CA. After passage of the pulmonary capillaries, the US-CA amplified blood flow signals in the arterial system in a dose-dependent manner with both systems used. Undesired side-effects were not observed. The amplification produced by appropriate concentrations of the US-CA markedly improved the visualization of blood movement. Further studies are required to determine the optimal dosage and application technique as well as the indication for using this US-CA.

Patología macro y microscópica de la hidatidosis humana / Macro and microscopic pathology of human hydatidosis

Se presenta la casuística de hidatidosis humana de la Sección Patológica de la Facultad de Medicina de la Universidad de Concepción, recopilada mediante sistema de diagnóstico codificado. Entre 5.195 autopsias realizadas de 1979 a 1989 había 30 casos (0,58 por ciento ) y en 81.832 biopsias estudiadas entre 1979 a 1990 había 266 casos (0,33 por ciento ). Predominó levemente el sexo masculino. Las edades mas afectadas en las biopsias estaban entre los 11 y 60 años y el órgano más afectado fue el hígado seguido del peritoneo, en los autopsiados en cambio la edad mñas afectada fue entre 41 a 80 años y el órgano fue el pulmón seguido del peritoneo. El diagnóstico se hizo en vida en la mitad de los 30 casos y en 14 de ellos en deceso fue atribuible a la enfermedad. 14 casos presentaron complicaciones, especialmente a nivel pulmonar. Revisamos la morfología macro y microscópica del parásito y las particularidades de su localizaciones basados en la literatura y experiencia local. Destacamos la concomitancia de 2 casos con un cáncer. Subrayamos la prevalencia de la enfermedad en nuestro medio con impacto en edades reproductivas, la gravedad de sus complicaciones, su significativa letalidad y la importancia de acciones preventivas

[Progeny in women with fetal alcohol syndrome]. / Descendencia en mujeres con síndrome alcohólico fetal.

Among children referred to our genetic clinics for mental or growth retardation we identified 8 of their mothers with the fetal alcohol syndrome. This was complete in 5 and partial in 3. All of their alcoholic mothers had died. Most of the patients were unwed mothers with mental retardation and no elementary education. One of them was also alcoholic and her third offspring had the syndrome. The etiology of this syndrome and possible preventive measures are discussed.

[Urodynamic results of Burch colposuspension]. / Urodynamische Ergebnisse der Kolposuspension nach Burch.

Between 1984 and 1987 31 patients underwent a colposuspension according to Burch for stress urinary incontinence. Seventeen women were available for clinical and urodynamic follow-up after an average of 17.6 months. Clinically, 2 women had postoperative stress-urge incontinence and 2 had stress incontinence only. 13 (77%) patients were continent while straining, 9 (53%) patients complained of urge and voiding disorders, 7 reported post micturition dribble, 2 patients lost urine during intercourse. Urodynamically, 14 (82%) patients were continent during straining, 3 showed mild stress incontinence. The functional urethra length and urethral closure pressure at rest were unchanged. The urethral pressure under stress, depression quotient, and transmission factor increased significantly. The average uroflow sank from 16.8 ml/s to 7.8 ml/s, reflecting the subjective voiding disorders. Bladder compliance was unchanged. We saw no autonomous detrusor contractions and thus no correlation with subjective urge complaints.

[Tuberculosis and diabetes mellitus: a longitudinal-retrospective study in a teaching hospital]. / Tuberculosis y diabetes mellitus: estudio longitudinal-retrospectivo en un hospital docente.

We analyzed 1529 diabetic patients seen between 1959 and 1982 at a teaching hospital in Concepción, Chile. 116 of them were insulin dependent diabetics. Gestational diabetes was excluded. The 10 year actuarial risk of acquiring tuberculosis was 24.2% for insulin-dependent diabetics and 4.8% for the rest (p less than 0.001). The risk of the diabetic population as a whole was 5.9% compared to 0.8% for the population at large. Thus, diabetics are a high risk group for tuberculosis, especially insulin-dependent patients whose risk is about 38 times higher than the general population under 40 years of age.