Partial coherence and frustration in self‐organizing spherical grids

Nearby grid cells have been observed to express a remarkable degree of long‐range order, which is often idealized as extending potentially to infinity. Yet their strict periodic firing and ensemble coherence are theoretically possible only in flat environments, much unlike the burrows which rodents usually live in. Are the symmetrical, coherent grid maps inferred in the lab relevant to chart their way in their natural habitat? We consider spheres as simple models of curved environments and waiting for the appropriate experiments to be performed, we use our adaptation model to predict what grid maps would emerge in a network with the same type of recurrent connections, which on the plane produce coherence among the units. We find that on the sphere such connections distort the maps that single grid units would express on their own, and aggregate them into clusters. When remapping to a different spherical environment, units in each cluster maintain only partial coherence, similar to what is observed in disordered materials, such as spin glasses.     

HIV or human papillomavirus co-infection among Brazilian individuals infected with hepatitis B and/or hepatitis C

Objective

To investigate the incidence of co-infection with HIV and human papillomavirus (HPV) among Brazilian individuals with hepatitis B virus (HBV) or hepatitis C virus (HCV) infection.

Methods

A prospective study was conducted that enrolled 103 individuals from the Ceará region of Brazil between January 4, 2010, and August 9, 2012. Eligible participants were men (n = 45) or women (n = 58) infected with HBV and/or HCV. Pap smears were collected from female patients. Material from male (urethra) and female (cervix) patients was then collected via DNA-HPV test and visual inspection with acetic acid.

Results

In all, 48 participants tested positive for HBV and 55 tested positive for HCV; 2 had dual infection with HBV and HCV. Co-infection with HIV was detected among 15 participants, whereas 20 participants were found to be co-infected with HPV.

Conclusion

A high prevalence of co-infection with HIV and HPV was detected among Brazilian individuals with HBV and/or HCV.     

A new shape for an old function: lasting effect of a physiologic surgical restoration of the left ventricle

Background  

Long-term morphofunctional outcome may vary widely in surgical anterior left ventricular wall restoration, suggesting variability in post-surgical remodeling similar to that observed following acute myocardial infarction. The aim of this pilot study was to demonstrate that surgical restoration obtained with a particular shape of endoventricular patch leads to steady morphofunctional ventricular improvement when geometry, volume and residual akinesia can be restored as normal as possible.     

Sentinel lymph node biopsy in breast cancer. Experience of the Rome Breast Cancer Study Group

We report our multicentric experience with sentinel lymph node biopsy for breast cancer patients. Patients with breast cancer operated on from January 1999 to March 2005 in 6 different institutions in the Rome area were retrospectively reviewed. All patients gave written informed consent. 1440 consecutive patients were analysed, with a median age of 59 years (range: 33-81) and a median tumour diameter of 1.3 cm (range: 0.1-5). Patients underwent lymphatic mapping with Tc99 nanocolloid (N = 701; 49%), with Evans Blue (N = 70; 5%), or with a combined injection (N = 669, 46%). The majority of patients were mapped with an intradermal or subdermal injection (N = 1193; 84%), while an intraparenchymal or peritumoral injection was used in 41 (3%) and 206 patients (13%), respectively. Sentinel lymph nodes were identified in 1374/1440 cases (95.4%), and 2075 sentinel lymph nodes were analysed (average 1.5/patient). A total of 9305 additional non-sentinel lymph-nodes were removed (median 6/patient). Correlations between sentinel lymph nodes and final lymph node status were found in 1355/1374 cases (98.6%). There were 19 false-negative cases (5%). Lymph node metastases were diagnosed in 325 patients (24%). In this group, micrometastases (< 2 mm in diameter) were diagnosed in 103 cases (7.6%). Additionally, isolated tumour cells were reported in 61 patients (4,5%). In positive cases, additional metastases in non-sentinel lymph-nodes were identified in 117/325 cases after axillary dissection (36%). Axillary dissection was avoided in 745/1440 patients (52%). At a median follow-up of 36 months, only 1 axillary recurrence has been reported. Sentinel lymph node biopsy improves staging in women with breast cancer because it is accurate and reproducible, and allows detection of micrometastases and isolated tumour cells that would otherwise be missed. Our multicentric study confirms that this is the preferred axillary staging procedure in women with breast cancer.     

Role of pulsed electromagnetic fields after joint replacements

Although the rate of patients reporting satisfaction is generally high after joint replacement surgery, up to 23% after total hip replacement and 34% after total knee arthroplasty of treated subjects report discomfort or pain 1 year after surgery. Moreover, chronic or subacute inflammation is reported in some cases even a long time after surgery. Another open and debated issue in prosthetic surgery is implant survivorship, especially when related to good prosthesis bone ingrowth. Pulsed Electro Magnetic Fields(PEMFs) treatment, although initially recommended after total joint replacement to promote bone ingrowth and to reduce inflammation and pain, is not currently part of usual clinical practice. The purpose of this review was to analyze existing literature on PEMFs effects in joint replacement surgery and to report results of clinical studies and current indications. We selected all currently available prospective studies or RCT on the use of PEMFs in total joint replacement with the purpose of investigating effects of PEMFs on recovery, pain relief and patients' satisfaction following hip, knee or shoulder arthroplasty. All the studies analyzed reported no adverse effects, and good patient compliance to the treatment. The available literature shows that early control of joint inflammation process in the first days after surgery through the use of PEMFs should be considered an effective completion of the surgical procedure to improve the patient's functional recovery.     

The impact of body mass index and central obesity on the spino-pelvic parameters: a correlation study

Introduction

Obesity is an increasing problem of epidemic proportion, and it is associated with various musculoskeletal disorders, including impairment of the spine. However, the relationship between obesity and spino-pelvic parameters remains to date unsupported by an objective measurement of the mechanical behavior of the spino-pelvic parameters depending on body mass index (BMI) and the presence of central obesity. Such analysis may provide a deeper understanding of this relationship.

Purpose

To assess whether BMI and central obesity are associated with modifications on spino-pelvic parameters and determine if exists any correlation between BMI and obesity with the type of lumbar lordosis (LL).

Methods

A cross-sectional study with 200 participants was conducted. Parameters measured were LL, pelvic tilt, sacral slope, and pelvic incidence (PI), using lumbosacral radiographs in lateral view. Subjects were classified depending on BMI. In a secondary analysis, the subjects were categorized into two groups depending on the presence or not of elevated abdominal circumference. The categorical variables were compared using Chi-square test, and the mean values were compared using ANOVA and student t test. A Spearman correlation test was used to analyze the correlation between BMI categories and LL types.

Results

From the total of participants, there were 51 (25.5 %) normal weight subjects, 93 (46.5 %) overweight, and 56 (28 %) obese individuals. The spino-pelvic parameters among these groups are practically equal. The correlation between the different BMI categories and LL types is poor 0.06 (P = 0.34). In a secondary analysis, grouping the participants in obese and non-obese, the results showed that obesity is modestly positively associated with increasing of spino-pelvic parameters values, in particular with PI (P = 0.078). The comparison made between the presence or not of central obesity, interestingly did not show significant differences.

Conclusions

Despite the results did not reach statistically significant differences, the results indicate that the obese spine is slightly different from the non-obese spine. Therefore, this relationship deserves future attention.     

Microsurgery for lymphedema: Clinical research and long‐term results

Objectives: To report the wide clinical experience and the research studies in the microsurgical treatment of peripheral lymphedema. Methods: More than 1800 patients with peripheral lymphedema have been treated with microsurgical techniques. Derivative lymphatic microvascular procedures recognize today its most exemplary application in multiple lymphatic‐venous anastomoses (LVA). In case of associated venous disease reconstructive lymphatic microsurgery techniques have been developed. Objective assessment was undertaken by water volumetry and lymphoscintigraphy. Results: Subjective improvement was noted in 87% of patients. Objectively, volume changes showed a significant improvement in 83%, with an average reduction of 67% of the excess volume. Of those patients followed‐up, 85% have been able to discontinue the use of conservative measures, with an average follow‐up of more than 10 years and average reduction in excess volume of 69%. There was a 87% reduction in the incidence of cellulitis after microsurgery. Conclusions: Microsurgical LVA have a place in the treatment of peripheral lymphedema, and should be the therapy of choice in patients who are not sufficiently responsive to nonsurgical treatment. © 2010 Wiley‐Liss, Inc. Microsurgery, 2010.     

Disentangling the Roles of Mammographic Screening and HRT in Recent Breast Cancer Incidence Trends in Italy by Analyses Based on Calendar Time and Time Since Screening Activation

Abstract: The aim of the study was to evaluate the roles of screening activation and hormone replacement therapy discontinuation on the recent declining breast cancer incidence trends in Italy. We analyzed 41,358 invasive female breast cancers incident during 1991–2004 in six Italian population‐based cancer registries. Overall and age‐specific incidence trends were evaluated using Joinpoint analysis. In addition to calendar years, data were analyzed on a years‐since‐screening‐activation basis. Annual percentage change of standardized rates was computed. There were statistically significant increasing trends for women 40–44 and 45–49 years that did not change after screening activation. On the contrary, for women 50–69 years old and for those 70+ years, the increasing trends flattened around 2 years after screening activation. The prevalence of hormone replacement therapy use in Italy is and was rather low. In conclusion, the recent tendency toward stabilization observed in Italy for female breast cancer incidence rates in women aged 50 years or more follows the introduction of mammographic screening.     

Detection of moderate and severe coronary artery stenosis with technetium-99m tetrofosmin myocardial single-photon emission tomography

The aim of this study was to determine the diagnostic accuracy of technetium-99m tetrofosmin myocardial imaging for the localization of coronary artery stenoses of different degrees of severity. Stress-rest single-photon emission tomography (SPET) was performed on separate days in 80 patients (64 males, 16 females; mean age 61 years; 43 patients with previous myocardial infarction; 18 patients with pharmacological stress), within 6 months of coronary angiography. Scintigraphic images were blindly and independently evaluated by three observers. Coronary stenosis was defined as a >50% narrowing in luminal diameter; severe stenosis was defined as a proximal stenosis of >75% or a peripheral stenosis of >90%. Coronary angiography revealed normal coronary arteries or insignificant coronary stenosis in 13 patients and significant coronary stenoses in 67 patients. The sensitivity and specificity of ^99mTc-tetrofosmin SPET in respect of severely stenosed vessels were, respectively, 80% and 65% for the left anterior descending artery (LAD), 100% and 46% for the right coronary artery (RCA) and 58 and 78% for the left circumflex artery (LCx) territories. Considering all the significantly stenosed vessels, a significant decrease in sensitivity was observed for LAD territories (to 59%, P=0.05), and a nonsignificant decrease for RCA (88%) and LCx (47%) territories while specificity values remained essentially unchanged. No significant changes in sensitivity or specificity were observed when regions with previous myocardial infarction were excluded. In conclusion, the sensitivity of ^99mTc-tetrofosmin SPET for the localization of individual stenosed vessels is only moderate when all significant stenoses are considered, but the ability of this technique to predict the location of severe coronary artery stenoses seems satisfactory, with the exception of the low specificity in respect of RCA territories. Received 26 April and in revised form 7 June 1997