An approach to the morphological disambiguation problem using conditional random fields

Morphology is the subfield of linguistics that studies the internal structures of words. Morphological analysis is the first step in revealing this structure by enumerating possible underlying morphological unit combinations that describe the surface form of a given word. The given surface form is said to be morphologically ambiguous, when more than one analysis corresponds to the given surface form. While words in every natural language may manifest morphological ambiguity, solving the problem of morphological disambiguation presents different challenges for different languages. In this work, we present an approach to this problem using Conditional Random Fields, a statistical framework that elegantly avoids data sparseness problems arising from the large vocabulary and tag set sizes, a characteristic of Turkish language. CRFs are used to build statistical models that rely on simple functions of easily testable properties of the training data at hand. Thanks to higher expressiveness gained by using tests on individual morphological markers, our results are in line with the state-of-the-art, using only a simple one-dimensional bigram chain model

Predictive factor for lymph node metastasis in non-metastatic colorectal adenocarcinomas

Objectives: To evaluate the predictive factors of lymph node involvement in non-metastatic colorectal adenocarcinomas (nmCRC). Methods: A total of 453 patients diagnosed with nmCRC were analyzed regarding T stage, lymphovascular invasion status, tumor grade and proposed risk score (RS), determined by the combination of these three factors for lymph node metastasis. Results: The median age was 62 (25-90 years), M/F ratio was 1.4:1 and majority of the patients had tumors localized on the left colon (70.6%). The number of excised lymph nodes was ≥12 in 77% of the cases. The postoperative pathological assessments revealed that 57.2% of patie,nts had N0 disease, 29.1% had N1 disease, and 13.7% had N2 disease. The T stages (p=0.007), grade (p<0.001), lymphovascular invasion (p=0.002), RS (p<0.001), and number of excised lymph nodes (p=0.029) were significantly different between N0, N1, and N2 patients. Higher RS was associated with lymph node metastasis (p<0.001). Conclusion: The risk score may predict lymph node metastasis in patients with nmCRC and if validated may be helpful in the decision-making of adjuvant chemotherapy, especially in the elderly and patients with inadequate lymph node dissection

Renal Hemangiopericytoma

Hemangiopericytoma is an uncommon perivascular tumor originating from pericytes in the pelvis, head and tneck, and the meninges; extremely rarely in the urinary system. We report a case of incidentally detected renal mass in which radiologic evaluation was suggestive of renal cell carcinoma. First, we performed partial nephrectomy, and then, radical nephrectomy because of positive surgical margins and the pathological examination of the surgical specimen that revealed a hemangiopericytoma. No additional treatment was administered

Maternal plasma levels of vitamin D in postterm pregnancy

This study was conducted to examine the levels of vitamin D in postterm pregnancy. The study consisted of two groups: Group 1: women with postterm pregnancy in whom labour has not started (n = 40). Group 2: pregnant women with spontaneous labour between 37 and 41 weeks of gestation (n = 40). Demographic characteristics of individuals, age, body mass index, gravida, parity, living child, number of abortions and birth characteristics were recorded. Prepartum and postpartum haemoglobin (Hb) and haematocrit (Hct) values ​​and vitamin D levels of pregnant women were measured. We found no significant differences in vitamin D levels, smoking, mode of delivery, induction of labour, methods of cervical ripening and maternal and perinatal complications between the groups (p > .05). D vitamin in the model had a statistically significant effect on prepartum Hb (p < .05). Vitamin D levels seem not to be associated with postterm pregnancy. Vitamin D had a statistically significant effect on prepartum Hb.IMPACT STATEMENT What is already known on this subject? The aetiology of post term pregnancy is not clearly known, factors such as foetal anencephaly, foetal sex, placental sulfatase deficiency, genetic factors, and high pre-pregnancy body mass index play a role. What do the results of this study add? Vitamin D levels seem not to be associated with postterm pregnancy. Vitamin D had a statistically significant effect on prepartum Hb. What are the implications of these findings for clinical practice and/or further research? Further studies are needed to clarify the relationship between vitamin D levels and postterm pregnancy

Prognostic significance of the programmed death ligand 1 expression in clear cell renal cell carcinoma and correlation with the tumor microenvironment and hypoxia-inducible factor expression

Abstract Background Clear cell renal cell carcinoma (ccRCC) is the most common renal malignancy. Hypoxia-inducible factors, HIF-1α and HIF-2α, are expressed in the majority of ccRCC. Targeting immune checkpoints with the blockade of PD-1 and its ligand PD-L1 reorganizes T-cell activity in tumor microenvironment and provides important antitumor responses. PD-L1 upregulation has been found to be hypoxia-inducible factor (HIF) dependent. Our aim is to demonstrate the association between PD-L1 and HIF expression and to reveal the role of PD-L1 in prognosis and its association with tumor microenvironment. Methods Surgical specimens from 145 patients diagnosed with ccRCC, who had undergone radical or partial nephrectomy, were retrospectively analyzed. Immunohistochemistry on tissue microarrays (TMA) was performed to demonstrate expressions of PD-L1, HIF-1α, and HIF-2α in tumor cells and PD-1, CD4, and CD8 in lymphocytes to assess lymphocyte density in tumor microenvironment. Results PD-L1 tumor cell expression was detected in 20/125 (13.8%) cases, which correlated with higher levels of PD-1, CD4, CD8 and HIF-2α expression. Low or high expression of HIF-1α was similar in PD-L1-positive cases. When PD-L1-positive cases were compared with negative ones, there was no significant difference in terms of prognostic factors. However, the number of WHO/ISUP grade 3–4 tumors was significantly higher in PD-L1-positive cases than in negative ones. Conclusion PD-L1 tumor cell expression is strongly associated with increased HIF-2α expression and presence of dense lymphocytic infiltration in ccRCCs. Our findings confirm that PD-L1 positivity is associated with high ISUP nucleolar grade. The association between PD-L1, HIF, and lymphocyte density in tumor microenvironment must be clarified and especially taken into account in combination treatment

Squamous Cell Carcinoma of the Bladder: 15 Years of Experience

Aim: To present our 15 years of clinical experience on squamous cell carcinoma (SCC) of the bladder. Methods: A total of 3590 patients with bladder tumors operated between September 1998 and May 2013 were retrospectively evaluated. A total of 42 patients with SCC confirmed by histopathology were included in this study. The patients’ characteristics, including age, gender, smoking history, tumor size, and location, pathological tumor stages, treatment modalities, and survival rates were all evaluated. Results: The median age of the patients at diagnosis was 62 years (range: 40-85) and the male-to-female ratio was 9.5: 1. The most common locations of tumors were left lateral, trigone, right lateral, posterior, dome, and bladder neck, respectively. Eight patients (16.7%) had metastasis at the time of diagnosis. Twenty-one patients underwent radical cystectomy and pelvic lymphadenectomy ± adjuvant treatment (chemotherapy/ radiotherapy) and 19 patients, who refused surgery, received radiotherapy ± chemotherapy. The median survival time in patients with squamous cell carcinoma who underwent radical cystectomy + adjuvant therapy was 27 months (range: 25-32) and 17 months (range: 16-19) in those who received radiotherapy + chemotherapy. Conclusions: SCC of the urinary bladder are aggressive tumors with low survival rates. The role of chemotherapy and radiotherapy in treatment is limited. Early radical cystectomy is a good treatment option for a favorable prognosis. (The Medical Bulletin of Haseki 2015; 53:192-5

Pediatric-Onset Chronic Inflammatory Demyelinating Polyneuropathy: A Multicenter Study

Background: To evaluate the clinical features, demographic features, and treatment modalities of pediatric-onset chronic inflammatory demyelinating polyneuropathy (CIDP) in Turkey. Methods: The clinical data of patients between January 2010 and December 2021 were reviewed retrospectively. The patients were evaluated according to the Joint Task Force of the European Federation of Neurological Societies and the Peripheral Nerve Society Guideline on the management of CIDP (2021). In addition, patients with typical CIDP were divided into two groups according to the first-line treatment modalities (group 1: IVIg only, group 2: IVIg + steroid). The patients were further divided into two separate groups based on their magnetic resonance imaging (MRI) characteristics. Results: A total of 43 patients, 22 (51.2%) males and 21 (48.8%) females, were included in the study. There was a significant difference between pretreatment and post-treatment modified Rankin scale (mRS) scores (P 0.05); however, a significant decrease was found in the mRS scores of both groups with treatment (P < 0.05). The patients with abnormal MRI had significantly higher pretreatment mRS scores compared with the group with normal MRI (P < 0.05). Conclusions: This multicenter study demonstrated that first-line immunotherapy modalities (IVIg vs IVIg + steroids) had equal efficacy for the treatment of patients with CIDP. We also determined that MRI features might be associated with profound clinical features, but did not affect treatment response