Mechanical properties and structure of the biological multilayered material system, Atractosteus spatula scales.

During recent decades, research on biological systems such as abalone shell and fish armor has revealed that these biological systems employ carefully arranged hierarchical multilayered structures to achieve properties of high strength, high ductility and light weight. Knowledge of such structures may enable pathways to design bio-inspired materials for various applications. This study was conducted to investigate the spatial distribution of structure, chemical composition and mechanical properties in mineralized fish scales of the species Atractosteus spatula. Microindentation tests were conducted, and cracking patterns and damage sites in the scales were examined to investigate the underlying protective mechanisms of fish scales under impact and penetration loads. A difference in nanomechanical properties was observed, with a thinner, stiffer and harder outer layer (indentation modulus ∼69 GPa and hardness ∼3.3 GPa) on a more compliant and thicker inner layer (indentation modulus ∼14.3 GPa and hardness ∼0.5 GPa). High-resolution scanning electron microscopy imaging of a fracture surface revealed that the outer layer contained oriented nanorods embedded in a matrix, and that the nanostructure of the inner layer contained fiber-like structures organized in a complex layered pattern. Damage patterns formed during microindentation show complex deformation mechanisms. Images of cracks identify growth through the outer layer, then deflection along the interface before growing and arresting in the inner layer. High-magnification images of the crack tip in the inner layer show void-linking and fiber-bridging exhibiting inelastic behavior. The observed difference in mechanical properties and unique nanostructures of different layers may have contributed to the resistance of fish scales to failure by impact and penetration loading.

[Magnetic resonance cholangiopancreatography: an advanced technique in the diagnosis of biliopancreatic diseases (the first experience in Panama)]. / Colangiopancreatografia por resonancia magnetica: una tecnica de avanzada en el diagnostico de las patologias biliopancreaticas (Primera experiencia en Panamá).

We evaluated the biliopancreatic pathology by a non invasive method of Choloangiqgraphy by Magnetc Resonance (the first experience in Panamá). We correlated the method with the retrograde cholangiopancreatography, the surgical findings and the clinical evolution. Our conclusion is that the non invasive method allows us to have confidence in the findings for the biliopancreatic pathology.

Application of an immunoassay to determine risk factors associated with porcine cysticercosis in rural areas of Yucatan, Mexico.

A Western blot assay for identification of 26 kDa and/or 8 kDa antigens in a crude saline extract (CSE) of Taenia solium metacestodes, previously developed for human cysticercosis, was evaluated for use with pigs. The test population used for assay standardisation consisted of 45 cysticercotic pigs (5 pigs positive by necropsy and 40 selected by tongue palpation and LL-Gp immunoblot but not confirmed by necropsy), 48 pigs with heterologous infections and 40 negative controls from endemic and non-endemic areas. The test detected 93% of the cysticercotic group and was 100% specific. In a field study this antigen preparation was compared by immunoblot with antibody recognition for Gp13-50 antigens in a lentil-lectin semi-purified glycoprotein extract of T. solium (LL-Gp). The seroprevalence to CSE antigen was slightly lower (26/75) when compared to LL-Gp (29/75) and this represented a non-significant difference. The CSE Western blot assay was used to assess seroprevalence of T. solium cysticercosis in pig populations in the state of Yucatan, Mexico. A total of 1099 pigs sampled at random from 25 villages revealed a seroprevalence of 23% (253/1099). Seroprevalence in intensively reared, farmed pigs was 2% (7/228). In comparison with farmed pigs, the seroprevalence was 33% (172/513) in free-roaming backyard pigs (OR=13.86, CI=4.0747.22, p<10(-6)) and 25% (74/98) in semi-confined backyard pigs (OR=14.03, CI=5.60-35.16, p<10(-6)). There was no significant difference in seroprevalence by sex (p=0.23). Seroprevalence decreased with age (chi(2)-test for linear trend=7.803, p<0.006). Results of this study demonstrate that the CSE Western blot can be applied for reliable immunodiagnosis of T. solium cysticercosis in pigs. Furthermore, variation in pig husbandry in Yucatan indicated significantly higher exposure to cysticercosis in free-roaming backyard pigs compared to intensively reared animals from the same area.

Teleradiología: la experiencia en Panamá / Teleradiology: the experience in Panamá

The technological advances have brought today procedures, that were not possible a few years ago. Telemedicine is one of them. Teleradiology in particular is one of the specialty where this application has been more important

[Teleradiology. The experience in Panamá]. / Teleradiología. La experiencia en Panamá.

The technological advances have brought today procedures, that were not possible a few years ago. Telemedicine is one of them. Teleradiology in particular is one of the specialty where this application has been more important.

Sonografia Duplex-Color en la evaluación dé la disfunción erectil de origen vascular / Duplex-color sonography in the evaluation of erectile dysfunction of vascular origin

The authors review the penile ultrasound records of 47 patients referred from the Urology Service with a diagnosis of Erectile Dysfunction. The pear systolic and and diastolic pressures were measured every 5 minutes for 30 minutes after the intracavernous injection of 60 mg of Papaverine, as well as the diameter of the cavernous arteries before and after the injection which was made using a 25 gauge needle. A tourniquet was applied at the base of the penis while injecting and was kept in place for 2 minutes after the injection was completed. The results were normal in 16 (34.04%) and abnormal in 31 (65.95%) patients. Of these, 27 (87.1%) had an abnormal vascular response and in 4 (12.9%) it was of an undetermined type. The abnormal vascular response was due to arterial insufficiency in 12 (44%) and to venous insufficiency in 15 (56%). The authors also found that the diameter of the cavernous arteries increased 15% to 120% (-/+ = 68%) in the patients with normal studies, 17% to 100% (-/+ = 58.1%) in those with arterial insufficiency and 23% to 89% (-/+ = 52.3%) in those with signs of venous insufficiency

In vitro responsiveness of Babesia bovis to imidocarb dipropionate and the selection of a drug-adapted line.

A South African stock of Babesia bovis was successfully resuscitated from liquid nitrogen, and cultured in microaerophilous stationary phase. The in vitro susceptibility of the B. bovis stock to titrated concentrations of imidocarb dipropionate was observed and the 50% inhibitory concentration (IC) was determined (8.7 x 10(7) g ml-1). A drug-adapted line was developed by culture in the presence of sub-inhibitory concentrations of imidocarb dipropionate and it had an IC50 eight times higher than that of its original stock (6.6 x 10(-6) g ml-1). The drug-adapted line was cryopreserved and resuscitated from liquid nitrogen. Continuous culture of the non-drug adapted line through 15 subcultures did not change the IC50 (8.3 x 10(-7) g ml-1).

[Duplex-color sonography in the evaluation of erectile dysfunction of vascular origin]. / Sonografia Duplex-Color en la evaluación dé la disfunción erectil de origen vascular.

The authors review the penile ultrasound records of 47 patients referred from the Urology Service with a diagnosis of Erectile Dysfunction. The pear systolic and and diastolic pressures were measured every 5 minutes for 30 minutes after the intracavernous injection of 60 mg of Papaverine, as well as the diameter of the cavernous arteries before and after the injection which was made using a 25 gauge needle. A tourniquet was applied at the base of the penis while injecting and was kept in place for 2 minutes after the injection was completed. The results were normal in 16 (34.04%) and abnormal in 31 (65.95%) patients. Of these, 27 (87.1%) had an abnormal vascular response and in 4 (12.9%) it was of an undetermined type. The abnormal vascular response was due to arterial insufficiency in 12 (44%) and to venous insufficiency in 15 (56%). The authors also found that the diameter of the cavernous arteries increased 15% to 120% (-/+ = 68%) in the patients with normal studies, 17% to 100% (-/+ = 58.1%) in those with arterial insufficiency and 23% to 89% (-/+ = 52.3%) in those with signs of venous insufficiency.

[The sonographic diagnosis of hypertrophic stenosis of the pylorus]. / Diagnóstico sonográfico de la estenosis hipertrófica del píloro.

The clinical records of 18 children were studied, between 15 and 60 days old. They were hospitalized due to vomiting and diagnosis of suspected pyloric hypertrophic stenosis (PHS). The sonography confirmed the diagnosis in 8 children, by the thickening of the muscular layer and enlargement of the pyloric canal. The surgery (pyloromyotomy) ratified the diagnosis in all 8 children. They all were in good health after being operated.

Diagnóstico sonográfico de la estenosis hipertrófica del píloro / The sonographic diagnosis of hypertrophic stenosis of the pylorus

The clinical records of 18 children were studied, between 15 and 60 days old. They were hospitalized due to vomiting and diagnosis of suspected pyloric hypertrophic stenosis (PHS). The sonography confirmed the diagnosis in 8 children, by the thickening of the muscular layer and enlargement of the pyloric canal. The surgery (pyloromyotomy) ratified the diagnosis in all 8 children. They all were in good health after being operated

[The sonographic diagnosis of hypertrophic stenosis of the pylorus]. / Diagnóstico sonográfico de la estenosis hipertrófica del píloro.

The clinical records of 18 children were studied, between 15 and 60 days old. They were hospitalized due to vomiting and diagnosis of suspected pyloric hypertrophic stenosis (PHS). The sonography confirmed the diagnosis in 8 children, by the thickening of the muscular layer and enlargement of the pyloric canal. The surgery (pyloromyotomy) ratified the diagnosis in all 8 children. They all were in good health after being operated.

Diagnóstico sonográfico de la estenosis hipertrófica del píloro / The sonographic diagnosis of hypertrophic stenosis of the pylorus

The clinical records of 18 children were studied, between 15 and 60 days old. They were hospitalized due to vomiting and diagnosis of suspected pyloric hypertrophic stenosis (PHS). The sonography confirmed the diagnosis in 8 children, by the thickening of the muscular layer and enlargement of the pyloric canal. The surgery (pyloromyotomy) ratified the diagnosis in all 8 children. They all were in good health after being operated

Evaluation of a colorimetric Babesia bigemina-DNA probe within an epidemiological survey.

An epidemiological survey was conducted in southeast Mexico, in an effort to establish the serological reactivity and carrier status to Babesia bigemina of an indigenous cattle population. The prevalence was obtained through the Indirect Fluorescent Antibody Test (IFAT), using an in vitro culture-derived B. bigemina antigen. A specific, digoxigenin-coupled, approximately 6 Kb B. bigemina-DNA probe (BBDP), was used to indicate the presence of the parasite. Serum samples from 925 animals of all ages, were obtained within the three regions (I, II, III) of the state of Yucatan and tested by IFAT. In addition, whole blood samples drawn from 136 of the same animals of region II were analyzed using the BBDP. Positive IFAT (IFAT+) reactions were observed in 531 sera for a 57% overall prevalence. Regional values were: I = 157+ (56%), II = 266+ (68%) and III 108+ (42%). Only 32 (23%) of the blood samples tested with BBDP showed distinctive hybridization signal, in contrast with 100 (73%) IFAT+ animals. The response distribution for IFAT vs. BBDP was: +/+ 23, +/- 77, -/+ 9 and -/- 27 respectively. It was found that the analytical sensitivity of BBDP appears to be low for its utilization in widespread epidemiological surveys. It was considered, however, that the colorimetric probe might be useful to safely detect transmission prone carriers, since it is able to detect parasitemias as low as 0.001%.

[Real-time sonography in the evaluation of peri- and intraventricular cerebral hemorrhage]. / La sonografía de tiempo real en la evaluación de la hemorragia cerebral peri e intraventricular.

Of 1776 sonograms done on 1312 patients with sector real time equipment, 923 done on 670 patients were selected because of suspected peri and intraventricular cerebral hemorrhage. The studies demonstrated hemorrhage in only 117 patients. It was possible to follow 107 patients and in 6.8 the hemorrhage was grade I, in 14 children it was grade II, in 19 it was grade II and in 6 it was grade IV. Most of the children (82 of 107) were pre-term (the average gestational age was less than 32 weeks). Twenty-three were term and two were post term. In most instances, the grade I hemorrhage resolved without sonographic or neurological sequelae, but in ten patients the hemorrhagic focus was replaced by a "cyst" which resolved in seven to more than 204 days; and in two it was replaced by a porencephalic cyst, which in one of the patients could still be seen at 134 days (when the last study was performed). All patients with grade II hemorrhage were pre-term (average gestational age of 33.1 weeks). Sonographic follow-up of these patients showed that hemorrhagic foci were not visible after 84 days (time of the last sonogram) and that only two children had slight hydrocephaly. Most of the children with grade III hemorrhage (75%) were premature (average gestational age of 32 weeks), and the others (25%) were at term. This was the group in which the greatest number of sonographic sequelae (e.g. hydrocephaly and/or atrophy) were observed. Also in this group more serious neurological sequelae were found. Grade IV Hemorrhage was found in the smallest number of patients but it had the worst prognosis: 2 of 2 premature babies died; 1 of 3 term babies died at 14 days after birth, another develop hydrocephaly and was operated on (developed cerebral palsy) and the third one was lost to follow up. A post term child with grade IV hemorrhage is being followed in the high risk clinic (at 10 months she has neurological sequelae which are not severe). At times it is difficult to differentiate grade IV hemorrhage from other conditions such as leukomalacia and/or peri-ventricular infarct. Real time sonography, performed through the anterior fontanelle has been shown to be very useful in the diagnosis and follow-up of peri and intraventricular cerebral hemorrhage.