Testing for nonlinearity in nonstationary time series: A network-based surrogate data test.

The classical surrogate data tests, which are used to differentiate linear noise processes from nonlinear processes, are not suitable for nonstationary time series. In this paper, we propose a surrogate data test that can be applied on both stationary time series as well as nonstationary time series with short-term fluctuations. The method is based on the idea of constructing a network from the time series, employing a generalized symbolic dynamics method introduced in this work, and using any one of the several easily computable network parameters as discriminating statistics. The construction of the network is designed to remove the long-term trends in the data automatically. The network-based test statistics pick up only the short-term variations, unlike the discriminating statistics of the traditional methods, which are influenced by nonstationary trends in the data. The method is tested on several systems generated by linear or nonlinear processes and with deterministic or stochastic trends, and in all cases it is found to be able to differentiate between linear stochastic processes and nonlinear processes quite accurately, especially in cases where the common methods would lead to false rejections of the null hypothesis due to nonstationarity being interpreted as nonlinearity. The method is also found to be robust to the presence of experimental or dynamical noise of a moderate level in an otherwise nonlinear system.

Risk of endometrial, ovarian and breast cancer in women with polycystic ovary syndrome: a systematic review and meta-analysis.

BACKGROUND: Polycystic ovary syndrome (PCOS) is a common condition affecting ∼8% of women. The objective of the present study was to quantify separately the risk of endometrial cancer, ovarian cancer and breast cancer in women with PCOS compared with non-PCOS controls, and quantify separately the risk to women of all ages as well as the risk to premenopausal women. METHODS: We conducted a systematic review and meta-analysis of observational studies. Studies were eligible for inclusion if they compared women with PCOS to non-PCOS groups for fatal or non-fatal gynaecological cancers. Studies listed in MEDLINE and EMBASE published up to 7 October 2013 in any language were identified, and relevant papers were also searched by hand. Relevant data (for example, study design, source of control data, diagnostic criteria) were extracted and tabulated. RESULTS: From 698 references, 11 studies (5 of endometrial cancer and 3 each of ovarian and breast cancer) met the inclusion criteria for the meta-analysis (919 women with PCOS and 72054 non-PCOS controls). Using the Mantel-Haenszel method, with fixed or random effects model as appropriate, women with PCOS were at a significantly increased risk of endometrial cancer (odds ratio (OR), 2.79; 95% confidence interval (CI), 1.31-5.95, P < 0.008), but the risk of ovarian and breast cancers was not significantly increased (OR, 1.41; 95% CI, 0.93-2.15, P < 0.11 and OR, 0.95; 95% CI, 0.64-1.39, P < 0.78, respectively). However when studies which included women aged over 54 years were excluded from the analysis, the risk for women with PCOS increased further for endometrial cancer (OR, 4.05; 95% CI, 2.42-6.76, P < 0.00001), became significantly increased for ovarian cancer (OR, 2.52; 95% CI, 1.08-5.89, P < 0.03), but remained non-significant for breast cancer (OR, 0.78; 95% CI, 0.46-1.32, P < 0.35). CONCLUSIONS: This is the first meta-analysis to examine gynaecological cancers in women with PCOS younger than 54 years of age compared with controls of similar age. Current data suggest that women of all ages with PCOS are at an increased risk of endometrial cancer but the risk of ovarian and breast cancer was not significantly increased overall. These results highlight the potential risk of gynaecological cancer morbidities associated with PCOS. However, the available evidence is far from robust and variation in diagnostic criteria for PCOS, associated risk factors (particularly obesity), and selection bias in the studies may have resulted in an exaggeration of the increased risk. Furthermore, women who have PCOS should also be made aware that any increased risk for endometrial cancer must be judged in the context of its relatively low incidence in the general population. A large well-controlled prospective study is required in order to gain a more accurate estimate of the risk of gynaecological cancers in women with PCOS. PROSPERO CRD REGISTRATION NUMBER: CRD42012003500.

Osseointegrated supported prosthesis and interdisciplinary approach for prosthodontic rehabilitation of a young patient with ectodermal dysplasia.

Anhidrotic ectodermal dysplasia is a triad of hypodontia or anodontia, hypotrichosis, and hypohydrosis, associated with other problems that result from the defective development of structures of ectodermal origin (Freire-Maia, Pinheiro (1988)). Early and extensive dental treatment is needed keeping in mind the effect on the craniofacial growth. Due to rapid growth of the jaws, the patients are rehabilitated using removable prostheses (Tarjan et al. (2005)). Hence for a young patient in this case report, the placement of endosseous osseointegrated implants was delayed till adulthood. Finally a definitive fixed tooth-supported and osseointegrated implant supported fixed partial denture therapy was used to rehabilitate the patient satisfactorily after she had completed her growth (Sweeney et al. (2005)). A review of the current literature relevant to several aspects of syndromic hypodontia, patient selection, and implant planning is discussed.

Multiple discharging sinuses: an unusual presentation caused by Absidia corymbifera.

A case of zygomycosis presenting with non-healing multiple discharging sinuses in a diabetic patient is reported here. The debrided tissue on histopathological examination revealed dense infiltration with aseptate fungal hyphae. Potassium hydroxide mount showed hyaline aseptate hyphae suggestive of zygomycosis. On culture, Absidia corymbifera was isolated. The patient responded to surgical debridement and therapy with amphotericin B followed by itraconazole.

Isolation, distribution and prevalence of various species of enterococci isolated from clinical specimens in a tertiary care hospital.

Various clinical specimens were processed to find the prevalence rate of enterococci and to identify the species of clinical isolates of enterococci. Screening of various clinical specimens revealed that enterococci were prevalent in 2% of the total specimens, with urine and wound to be the major site of isolation. Conventional test scheme proposed by Facklam and Collins and commercially available systems Rapid ID 32 Strep (biomereiux) were successfully used to speciate enterococcal strains. Five species of enterococci were identified in the study from a set of 396 cultures, with E. faecalis (79.79%), and E. faecium (11.11%) predominating. E. hirae (3.03%), E. gallinarum (3.03%), and E. casseliflavus (3.03%), were the other members of Enterococcus species identified.

Superantigens - concepts, clinical disease and therapy.

The term superantigen was introduced in microbiology and immunology only a decade ago. The unique feature of superantigen is that it bypasses the antigen processing mechanism and specifically binds to TCR v segment and forms a trimolecular complex along with major histocompatibility complex class II. Since its discovery, several studies have been carried out to unravel the properties of superantigens. They are implicated in the pathogenesis of diseases of bacterial, viral and fungal origin. They are also known to play a role in autoimmune diseases. Therapy for these superantigens is being worked upon. Studies have shown that intravenous gamma globulin containing specific antibodies to these superantigens inhibits the activation of T-Cells and also the cytokine production by them resulting in dramatic recovery from superantigen mediated diseases. The use of superantigen in the therapy of cancer is being explored.

Prevalence of bacterial vaginosis in antenatal women.

Bacterial vaginosis is an established risk factor in pregnant women for premature rupture of membranes and preterm delivery. This study was carried out to find out the prevalence of Bacterial Vaginosis (BV) in antenatal women with vaginal discharge and the effect of treatment with Metronidazole gel on pregnancy outcome. One hundred and fifty symptomatic and fifty asymptomatic women in second trimester of pregnancy in the age group of 20-30 years were included in the study. Gram stained smears of vaginal discharge were examined for evidence of BV with a scoring system by Nugent et al and was found to be positive in 38.5% in symptomatic antenatal women. Intravaginal metronidazole gel application was found to be an effective therapeutic option. Incidence of preterm labour was more in untreated cases.

Studies on the incidence of leptospirosis and possible transmission of Leptospira during leptospiraemia.

During the year 1991 and in the first half year of 1992 a total of 179 cases and 288 cases respectively were tested for the presence of Leptospira by dark ground microscopy and 86 cases (48%) and 157 cases (54.5%) were found to be positive for Leptospira in their blood samples only. The disease was endemic and more prevalent in the age group of 5 to 14 years and 15 to 54 years and affected both sexes. Clinical categorisation of 169 cases in 1991 and 266 cases in the first half of the year 1992 along with the dark ground microscopy results showed that there was no strict correlation between the concentration of Leptospira in the blood and the severity of infection. Epidemiological data regarding the occupation and the contacts indicated that students and medical staff accounted for more than fifty percent of leptospiral infection and there was the possibility of transmission of Leptospira during leptospiraemia. Dark ground microscopy studies on blood samples from 20 cases who came for repeat testing showed the presence of Leptospira in blood up to 43 days and suggested that the convalescent carrier may have a role in the transmission of Leptospira during Leptospiraemia.

MHA-Tp testing on HIV positive and negative women in vigilance home at Madurai.

In the study group of 94 cases of female prostitutes and their children 55 cases showed positive for HIV infection by ELISA and Western Blot tests. They showed positive also for syphilis in 37 cases by VDRL and in 43 cases by MHA-Tp tests among HIV positive and negative women. The association of HIV infection and syphilis was observed in this study due to sexual transmission of these infections. But congenital spread from infected mother to their children was not observed in this study since both mothers and their children were negative for these infections. MHA-Tp testing confirmed VDRL test results in 27 cases and also increased specificity of MHA-Tp test result over VDRL result in 16 cases and exclusion of biological false positive by VDRL in 10 cases were noticed in this study.

PIP: In June-July 1990, in India, 86 former prostitutes of Tamil Nadu origin who lived in Bombay for many years and recently returned to Vigilance Home in Madurai were tested for HIV and syphilis. 8 of their children were also tested. None of the cases exhibited signs of HIV infection or syphilis. The ELISA test revealed 55 positive HIV cases (58.5%), but the Western Blot test confirmed 47 cases to be definitely HIV positive. The remaining 8 cases had unclear Western Blot results. The VDRL test for syphilis identified 37 cases (39.3%), while the MHA-Tp test identified 43 cases (45.6%). MHA-Tp confirmed syphilis in 27 VDRL cases. 16 MHA-Tp positive syphilis cases had a nonreactive VDRL result, suggesting past/treated infection of syphilis. This also showed that MHA-Tp had a higher specificity than did VDRL. MHA-Tp revealed 10 false positive cases. 23 HIV-positive cases tested positive for syphilis with the VDRL test. With the MHA-Tp test, 27 HIV positive cases tested positive. All 8 children and their mothers tested negative for HIV (ELISA) and syphilis (VDRL and MHA-Tp), indicating that no congenital transmission of HIV or syphilis occurred in this population.