Supermagnonic Propagation in Two-Dimensional Antiferromagnets

We investigate the propagation of magnons after ultrashort perturbations of the exchange interaction in the prototype two-dimensional Heisenberg antiferromagnet. Using the recently proposed neural quantum states, we predict highly anisotropic spreading in space constrained by the symmetry of the perturbation. Interestingly, the propagation speed at the shortest length scale and timescale is up to 40% higher than the highest magnon velocity. We argue that the enhancement stems from extraordinary strong magnon-magnon interactions, suggesting new avenues for manipulating information transfer on ultrashort length scales and timescales.

Pharyngeal airway changes in pre-pubertal children with Class II malocclusion after Fränkel-2 treatment

AIM

To evaluate two-dimensional changes in pharyngeal airway dimensions in pre-pubertal children with a Class II malocclusion treated with a Fränkel-2 appliance compared to a matched non-treated control sample.

MATERIALS AND METHODS

Lateral cephalograms obtained from 28 consecutively treated pre-pubertal children before (T0) and after (T1) a one-year Fränkel-2 treatment were analysed. Fränkel-2 appliance was used for at least 18 hr/day during 12 months. The control group was matched as closely as possible. All the cases presented normal facial growth pattern. Sagittal and vertical cephalometric measurements assessing maxillary and mandibular skeletal positions, as well as sagittal pharyngeal airway dimensions, were calculated. Intraclass correlation coefficient was calculated in order to determine reliability. Differences based on age for all the outcome variables at T0 were compared with an independent t-test. A MANOVA was used thereafter to determine if any factors and their interactions were associated with changes in the outcome variables. Differences between T1 and T0 were evaluated with either a t-student test or a Mann Whitney U test.

RESULTS

At T0 differences between groups were noted for several variables. These differences were considered during the follow-up statistical analysis. Changes between groups after treatment (T1-T0) were noted for SNB, PNS to Ba, McNamara Low and Middle to S (increase in treatment group), and ANB and AD1 to Ba (decrease in treatment group).

CONCLUSIONS

Some pharyngeal two-dimensional airway dimensions changed in Class II malocclusion pre-pubertal patients during a one-year treatment with Fränkel-2 appliances.

Dentoskeletal features in mixed dentition children with displaced maxillary canines in a southern Italian population

AIM

To analyse the prevalence and the distribution of displaced, buccal/palatal maxillary canines, and the association with sagittal and vertical skeletal relationships in a southern Italian population.

MATERIALS AND METHODS

Consecutive records of patients were examined. Inclusion criteria were: age 7-12 years, 1-2 cervical vertebral maturation (CVM) stage, initial dental casts, intraoral photographs, panoramic, lateral and periapical radiographs. Subjects with at least one canine in Lindauer II, III or IV sector and/or α angle >31° were included in displaced maxillary canine (DMC) group, whereas those with both canines in sector I and α angle ≤31° were used as control group (CTR). According to canine bulges and/or x-ray examinations, DMC were then divided in palatal and buccal displaced canines (PDC/BDC). Sagittal and vertical skeletal relationships were evaluated using ANB and SN/GoMe angles. Chi-square tests were performed to compare the prevalence rates of skeletal features.

RESULTS

The sample consisted of 123 children, 40 DMC and 83 CTR. The DMC group included 11 PDC and 29 BDC subjects. The M:F ratio was 1:3 in PDC and BDC, 1:1 in CTR group. The unilateral-to-bilateral ratio was 1:1 and 3:1 in PDC and BDC subjects. The most common sector combination regarding unilateral and bilateral displacements was "II" and "II,II". PDC occurred more in Class I and in hyperdivergents, whereas BDC in Class I or II and in normodivergents.

CONCLUSIONS

DMC occurred more often in females than in males. BDC was more common than PDC and unilateral displacements occurred more frequently than bilateral ones. No significant correlation with skeletal features was observed.

Identification of patients with high osteoporosis risk: analysis of FRAX and phalangeal ultrasonography in a female population in North-East Italy

AIM

Osteoporosis is a worldwide health problem and bone fractures from osteoporosis are among the major causes of disability, with a great impact on the national health budgets. The aim of our study was to analyze the efficacy of FRAX algorithm and phalanger ultrasound to predict the risk of osteoporotic fractures, in order to identify a high risk population to examine with a second level diagnostic analysis.

METHODS

The study population was composed of 1208 premenopausal, perimenopausal, and postmenopausal women, between 40 and 81 years. For each woman phalangeal QUS was performed and FRAX index was calculated. The FRAX index was evaluated according to standard plots available on web (http://www.shed.ac.uk/FRAX/index.htm).

RESULTS

Analysing the correlation between women age and phalanger bone ultrasound values we know that all parameter decrease with increasing of age. We found a significant difference between FRAX index and the ultrasound parameters (P<0.05) to predict a major osteoporotic fracture, we did not find differences between age and ultrasound parameters. Furthermore, we show that after correction per age of the women the ultrasound parameters lose their significant correlation with major osteoporotic fractures. Finally, FRAX index showed a good AUC and in our population and a 10-year probability over 9.4% of major osteoporotic fractures had a good specificity (88%) and sensitivity (83%) to predict osteoporotic fractures.

CONCLUSION

Our data suggest that FRAX index alone could be used to address high risk women to more invasive tests but we need more data about ultrasound parameters.

[Hormone replacement therapy and urogenital disease in postmenopausal women]

Estrogen deficit in postmenopausal women causes urogenital atrophy, which is responsible for a wide range of urinary disorders (urinary incontinence, urge incontinence, recurrent urinary infections) and genital disorders (prolapse, dispareunya, vaginal dryness). The efficacy of estrogen therapy on urinary incontinence is not yet demonstrated, but it is widely recognized that the topical use of estrogens lowers the risk of recurrent urinary infections and improves urogenital atrophy.

[Retrospective analysis of one year of cesarean sections: indications and risk factors associated with intrapartum cesarean section]

AIM

Cesarean section (CS) is currently the most commonly performed surgical intervention worldwide. Indications include previous CS, podalic presentation and fetal macrosomia in antepartum CS, fetal distress, and prolonged first or second phase of labor in intrapartum CS. Despite the marked reduction in fetal mortality and morbidity in selected circumstances, maternal complication rates associated with CS are far higher than with vaginal delivery. The aim of this study was to evaluate the indications and maternal and fetal outcomes in a population undergoing antepartum or intrapartum CS and to analyze the risk factors of intrapartum CS.

METHODS

An analysis was conducted on data from 1748 deliveries performed at the Gynecology-Obstetrics Clinic of the University of Udine during 2006. A total of 603 medical records of the mothers who had delivered by CS and their infants were analyzed. The Indications and maternal and fetal outcomes were evaluated in mothers who had undergone elective CS, emergency antepartum or intrapartum CS; multivariate analysis was then performed to define the risk factors associated with intrapartum CS.

RESULTS

Cesarean sections accounted for 34.5% of all deliveries performed during 2006, of which 42.1% were elective CS, 21.1% emergency antepartum CS, and 36.8% intrapartum CS. The principal reason for CS delivery was previous CS in elective CS, gestational hypertension in emergency antepartum CS, and cardiotocographic alterations in emergency intrapartum CS. Multivariate logistic regression analysis showed that the independent risk factors for intrapartum CS were excessive weight gain during pregnancy and medically induced labor.

CONCLUSION

A more accurate evaluation of the mother's and neonate's needs could help to improve the current rates of CS. This could be achieved by selection of cases in which there is a real need for CS and by acting on modifiable risk factors of intrapartum CS such as excessive weight gain during pregnancy.

Identification of patients with a high risk of osteoporosis. Analysis of risk factors, ultrasonography and DEXA, in a female population in the North East of Italy

AIM

The aim of this observational study is the identification of women at high risk of osteoporosis by using the phalangeal quantitative ultrasound (QUS) value for osteoporosis screening.

METHODS

The study population is composed of 1 152 women between 35 and 79 years old, both premenopausal and postmenopausal. Each woman underwent a questionnaire and phalangeal QUS. One hundred and forty-eight women also underwent dual energy X-ray absorptiometry (DEXA). Osteopenia and osteoporosis, as determined using the amplitude dependent speed of sound (AD-SoS) T-score, identified women at a high risk of fracture. Data were stored and analyzed using SPSS (Statistical Package for Social Science) for Windows.

RESULTS

AD-SoS is significantly higher in premenopausal women than in postmenopausal women without history of hormone replacement therapy (HRT) (P<0.001), if they are over 50 years old. In women 50-59 years old, AD-SoS is significantly higher in premenopausal women than in postmenopausal women with or without HRT history (P<0.001). In postmenopausal women, discriminant analysis found that HRT and years of HRT are the only significant protective factors (P<0.001). In premenopausal and postmenopausal women with no history of HRT use, discriminant analysis demonstrated that early menopause and a family history of osteoporosis are the only significant risk factors (P<0.001).

CONCLUSION

Early menopause and a family history of osteoporosis seem to be the greatest risk factors, while HRT seems to be a protective factor. The QUS technique, with DEXA as a secondary test, can be a screening test for the identification of postmenopausal women with a high risk of fracture.

Postmenopausal hormone therapy and mammographic breast density

OBJECTIVE

The aim of this study was to evaluate the effects of different types of hormone replacement therapy (HRT) on mammographic density.

MATERIALS AND METHODS

In a prospective 1-year study, 103 postmenopausal women were randomized to receive tibolone 2.5 mg/die, continuous conjugated equine estrogens 0.625 mg/die plus medroxyprogesterone acetate (MPA) 5mg/die or placebo. Mammograms were performed at baseline and after 12 months of treatment. Mammographic density was quantified according to the Wolfe classification.

RESULTS

After 12 months of HRT 16 of the 35 patients (45.1%) receiving continuous combined hormonal therapy showed an increase of breast density change in the Wolfe classification. After treatment with tibolone, an up grading in breast density, according to Wolfe's classification, was found in 2 of the 43 patients (2.3%). No changes were recorded in the 25 patients of the control group. The difference between the group treated with continuous combined hormonal therapy and the control group was highly significant (p<0.001). The difference in breast density between patients in treatment with tibolone and the control group was not statistically significant (p=0.34).

DISCUSSION

Continuous combination HRT may be more commonly associated with an increase of mammography density than tibolone treatment.

Endometrial histologic changes in post-menopausal breast cancer patients using tamoxifen

OBJECTIVE

The aim of this study was to evaluate the effect of tamoxifen on the endometrium of post-menopausal women with breast cancer and to examine the relationship between ultrasonography, hysteroscopy and histopathologic changes.

METHOD

Included in this longitudinal study were 303 post-menopausal women taking 20 mg daily of tamoxifen. Hysteroscopy was performed in 83 patients with an endometrial thickness of only >or=5 mm and 34 with vaginal bleeding also. Forty-five asymptomatic patients (control group) underwent hysteroscopies.

RESULT

The most frequent outcome in patients with endometrial thickness of only >or=5 mm was an atrophic endometrium in an empty cavity (79.5%) whereas simple hyperplasia (35.3%) was found in women with vaginal bleeding. Carcinoma was diagnosed in seven cases (5.9%). In the control group, no endometrial cancer was found.

CONCLUSION

This study suggests that patients with a thickness >5 mm should be offered a whole hysteroscopic evaluation, whenever bleeding is reported.

Neuro-Behçet: report of three clinically distinct cases

We report three patients who collectively have very representative clinical forms of neuro-Behçet and different neurological findings. The first case, male, 49 years old, presents symptoms similar to multiple sclerosis. The second case, male 15 years old, presents with parenchymatous compromise and an association with antiphospholipid antibody. And the third case, female 25 years old, presents an acute meningitis. Neuro-Behçet must always be included as a differential diagnosis of neurological disorders that have any difficulties in establishing a definite diagnosis.

Palatal myoclonus: report of two cases

We describe two cases of palatal myoclonus (PM), one essential and another secondary to a stroke. Case 1: a 64 years old female who developed clicking sounds in both ears after a stroke and three years later on noticed a progressive involuntary movement of the throat associated with rhythmic contractions of the soft palate, muscles of tongue and throat. MRI showed an ischemic area in brainstem. The patient had a partial response to the use of sumatriptan 6 mg subcutaneously. Case 2: a 66 years old female who began with ear clicking at left ear that worsed slowly associated with tinnitus and arrhythmic movements of soft palate and an audible click at left ear. Brain MRI was normal; audiometry showed bilateral neurosensory loss. She was prescribed clonazepan 1 mg daily with complete recovery. Primary and secondary palatal myoclonus share the same clinical features but probably have different pathophysiological underlying mechanisms.

[Clinical and therapeutical features in 135 patients with dystonia: experience of movement disorders unity of the Hospital de Clínicas of the Universidade Federal do Paraná]

This study aims to describe the clinical patterns and therapeutic responses in 135 patients with dystonia. According to the classification, 54% were focal; 17.8% were segmental; 8.1% hemidistonia; 18.6% generalized and 1.5% were multifocal. There was a positive familial history in 5.9% of the cases. The treatment of the idiopathic dystonias is divided in: specific and symptomatic, and it can be local with botulinum toxin, or systemic with oral drugs. The most common drugs used in the treatment were anticholinergics and benzodiazepines, with poor responses in the generalized forms. Botulinum toxin A was the first line treatment for focal and segmental forms of dystonia. Meanwhile, the generalized forms of dystonia show poor response to the therapies utilized.

Perivascular astrocytes and endothelium in the development of the blood-brain barrier in the optic tectum of the chick embryo

The role played by perivascular astrocytes in neural vessel maturation was investigated in microvessels of the chick embryo optic tectum. Three-dimensional reconstructions and quantitative analyses were made, and permeability was studied. On embryonic days 14-16, 12.5% of the microvessel wall is surrounded by astrocyte endfeet which, in most cases (82%), are located under endothelium junctions; the latter, at this stage, partly prevent the extravascular escape of the marker horseradish peroxidase. On days 18-21, the astrocyte processes form a nearly complete perivascular sheath enveloping 96% of the microvessel perimeter; the junctions of the endothelial cells are much wider and impermeable owing to extensive fusion of the endothelial plasma membranes. This investigation suggests a close relationship between the perivascular arrangement of glia and differentiation of the endothelium tight junctions and indicates that the morphofunctional maturation of the latter takes place progressively during the prenatal organogenesis of the chick central nervous system.

[Production of interferon after infection by various doses of "Plasmodium berghei" in mice (author's transl)]

Groups of mice were inoculated with either low or high intraperitoneal doses of Plasmodium berghei infected erythrocytes (PIE). The course of infection was observed daily by counting new PIE which appeared in the red blood cells (RBC) of infected mice. At the same time, circulating interferon (IF) was tested. When low doses of infecting PIE were used (400 per mouse), circulating IF was first detected on the 5th day after inoculation. It increased to a maximal rate, when 5% of RBC were affected. It disappeared on the 8th day despite of a continuous rise of PIE. With high doses of PIE (60,000 per mouse), IF was detected on the 3rd day, when only 0.5% of RBC were parasitized. The maximal rate was observed on the 5th day when 20% of the RBC were affected. It disappeared on the 7th day, though the PIE rate would continue to rise. Treatment of mice by chloroquine (0.01 per g), at the time of first PIE appearance after Plasmodium infection, rapidly reduced the amount of PIE. In this case, no IF production was observed. Splenectomy resulted in an increased resistance of mice to the lethal effect of Plasmodium infection. IF production in such splenectomized mice was less important than in control. It was concluded that P. berghei was a good inducer of circulating IF at the beginning of the active disease, soon after infection. The fact was proven by the striking lowering effect of chloroquine and splenectomy that both reduced Plasmodium development and IF production.

[Opportunistic microbial infections and their importance in general pathology]

Opportunist germs are commensal bacteria or fungi of the skin and mucosae or saprophytes of the external media, which become virulent when general or local resistance of the organism is lowered. Under the influence of favouring factors, mainly certain drugs, infections due to opportunist germs are becoming more and more frequent, mainly in hospitals, constant or occasional contact of man with these bacteria make diagnosis and prophylaxis of their infections difficult.

[New plasmid resistance of Staphylococcus aureus to aminosides (gentamicin, tobramycin, amikacin]

Recently, strains of Staphylococcus aureus resistant to gentamicin, tobramycin and amikacin have been discovered in several hospitals in France. These new resistances, of two different types, are of plasmid origin and of enzyme mechanism. This study describes their current incidence.

[The problem of systematic bacteriological examinations carried out early in premature infants]

Systematic bacteriological examinations of samples taken from the pharynges, the gastric juices and the meconium or the ano-rectal regions were carried out on 300 premature babies immediately on their admission to hospital. These examinations, which consisted in direct microscopic examination and in culturing the specimens, showed that usually a normal microbial flora was established in the mucous membranes of the digestive tracts but there were also abnormalities caused by contamination. There is therefore a limited but real value in the tests when they reveal massive bacterial contamination by the presence of microbes that could be at this stage of life dangerous to a premature baby. The results of the tests then suggest the necessity for antibiotic therapy.

Interactive system for automatic analysis of human R-banded metaphases

A computer system analysing human metaphase images and finding banding patterns of R-banded chromosomes has been set up. This first paper describes the interactive procedure in selection of metaphase images, automatically digitized starting from microphotographic negatives.