Central airway obstruction due to malignant fibrous histiocytoma metastasis in a case with Mounier-Kuhn syndrome

Malign fibrous histiocytoma is one of the most observed soft tissue sarcomas seen in the adults. The most common metastasis region is the lung and metastasis. Mounier-Kuhn syndrome is characterized by the highly dilatation of the trachea and bronchi. We may encounter with the major airway obstruction in the endoluminal or extraluminal lung and mediastinal masses or those with both components together. In this article, we would like to highlight the occurrence of a rare seen clinical situation secondary to the giant mediastinal malign fibrous histiocytoma metastasis and the clinical difficulties experienced in resolving of the main airway obstruction caused by the mass. Since the lack of the similar studies conducted previously, we found the case worth presenting.     

Multiple telomeric aberrations in a telomerase-positive leukemia patient

Bone marrow samples from a pancytopenia/leukemia patient were routinely analyzed at first and second admission. At the first presentation, the karyotype was normal, whereas 17 months later several chromosome aberrations were recognized including presumed additions to the short arms of chromosomes 1 and 16 in all cells, and numerous other aberrations in subpopulations of cells. From the predominance of aberrations at chromosome ends, we suspected insufficient telomere maintenance as an underlying mechanism behind the karyotype changes, in particular as an interstitial deletion in the region harboring the gene for the RNA component (hTERC) of the telomerase enzyme was also noticed; however, while molecular cytogenetic investigation confirmed the terminal aberrations, we found the malignant cells positive for telomerase activity and the presence of an hTERC gene on both chromosomes 3. A presumed chromosome 1 addition turned out to reflect an amplification of a tandemly repeated sequence element. Labeling of multiple tandem repeat sequences in situ by a novel multicolor primed in situ hybridization showed no evidence of instability of other repeated DNA elements.     

Road for understanding cancer stem cells: model cell lines

There is increasing evidence suggesting that stem cells are susceptive to carcinogenesis and, consequently, can be the origin of many cancers. Recently, the neoplastic potential of stem cells has been supported by many groups showing the existence of subpopulations with stem cell characteristics in tumor biopsies such as brain and breast. Evidence supporting the cancer stem cell hypothesis has gained impact due to progress in stem cell biology and development of new models to validate the self-renewal potential of stem cells. Recent evidence on the possible identification of cancer stem cells may offer an opportunity to use these cells as future therapeutic targets. Therefore, model systems in this field have become very important and useful. This review will focus on the state of knowledge on cancer stem cell research, including cell line models for cancer stem cells. The latter will, as models, help us both in the identification and characterization of cancer stem cells and in the further development of therapeutic strategies including tissue engineering.     

Efecto de la hipoxia sobre el metabolismo de la glucosa en pacientes no diabéticos con síndrome de apnea obstructiva del sueño

Aim

Obstructive sleep apnea syndrome (OSAS) may promote hyperglycemia and insulin resistance. Our aim is to investigate the effect of OSAS on the fasting plasma glucose, glycosylated hemoglobin (HbA_1c), and C reactive protein (CRP) in nondiabetic patients.

Material and methods

Blood parameters of consecutive 90 non diabetic patients whom polysomnografic evaluations were done in our sleep laboratory was evaluated. Among these 61 patients with normal fasting blood glucose were classified due to their apne-hipopnea index (AHI) as mild (n = 16, 26.2%), moderate (n = 18, 29.5%) and severe (n = 27, 44.2%) OSAS. The fasting plasma glucose, HbA_1c and CRP were measured.

Results

Mean age of the patients was 47.7 ± 11.2 years, 72% male. HbA_1c, fasting glucose levels show positive correlation with BMI (r = .503, P = .00; r = .258, P = .045). No relation of HbA_1c to apnea index nor AHI was detected while positive corelation of fasting glucose and CRP was detected (r = .262, P = .042; r = .258, P = .045). HbA_1c, fasting glucose and CRP levels show negative correlation with minimum SpO₂ levels (by order of r = –.302, P = .018; r = –.368, P = .004; r = –.365, P = .004). HbA1c, fasting glucose levels and CRP levels show positive correlation with mean desaturation index (time duration in which SpO₂ < 90% by pulse oxymeter) (r = .263, P = .041; r = .311, P = .015; r = .283, P = .027).

Conclusions

Although no relation in between increased HbA_1c or glucose levels and severity of OSAS was detected in nondiabetic OSAS patients, the correlation with the night hypoxia was detected. This could also show the effect of night time hypoxia on glucose metabolism in OSAS patients.     

Telomerase promoter reprogramming and interaction with general transcription factors in the human mesenchymal stem cell

The human adult mesenchymal stem cell (hMSC) does not express telomerase and has been shown to be the target for neoplastic transformation after transduction with hTERT. These findings lend support to the stem cell hypothesis of cancer development but by supplying hTERT, the molecular events required to upregulate hTERT expression in cancer development are missed. Therefore, the hMSC is ideal for the identification of molecular mechanisms regulating telomerase gene expression in stem cells. This study shows that the repression of hTERT expression in hMSC is chromatin based and that modifications of the chromatin environment lead to reactivation of telomerase gene expression. It is shown that repression of hTERT expression in hMSCs is due to promoter-specific histone hypoacetylation coupled with low Pol II and TFIIB trafficking. This repression is overcome by treatment with Trichostatin A (TSA), an HDAC inhibitor, concomitant with increases in promoter-specific histone acetylation and increases in Pol II and TFIIB tracking. hTR expression is also increased in TSA-treated hMSCs, concomitant with changes in Pol II and TFIIB dynamics.     

Semirigid thoracoscopy in the diagnosis of pleural effusion: first four cases in Turkey

Medical thoracoscopy is a valuable tool in the management and investigation of pleural diseases. It has advantages when compared to conventional closed pleural biopsy and video-assisted thoracoscopic surgery. However, the use of this technique is limited in Turkey. The present report is about the first experience with semi-rigid thoracoscope that was implemented in our country. Four patients underwent medical thoracoscopy in September 2009 with the new device. All patients were referred due to non-diagnostic closed pleural biopsy. The use of the device was simple and fabulous views were obtained. All biopsy specimens of the 4 patients were histologically adequate. Definite diagnosis was enabled in 3 of the 4 patients when clinical features and CT findings combined with thoracoscopic specimens. The design is similar to the fiberoptic bronchoscope, respiratory physicians can easily adapt to its use. It is also compatible with most video operating systems and light sources used in endoscopy suites. The convenient use and compatibility with most endoscopic systems are raising the importance of the device. However, biopsy size from semirigid thoracoscope might cause diagnostic difficulty when compared to rigid thoracoscope.     

Influence of glycosylated hemoglobin on the choroidal thickness

Purpose

The aim of the study reported here was to assess the influence of serum HbA1c levels on foveal choroidal thickness in diabetic patients.

Methods

A total of 122 eyes from 122 patients who had type 2 DM were studied in this prospective, cross-sectional study. Patients were divided into three groups: 43 patients (43 eyes) without diabetic retinopathy (NDR), 39 patients (39 eyes) with diabetic retinopathy and no macular edema (DR/ME?), 40 patients (40 eyes) with diabetic retinopathy and macular edema (DR/ME+). Central foveal thicknesses and subfoveal choroidal thicknesses were noted. Subfoveal choroidal thickness measurement was taken perpendicularly from the outer part of the retinal pigment epithelial layer to the line corresponding to the choroidal–scleral junction. Serum glycosylated hemoglobin (HbA1c) levels were evaluated.

Results

No significant differences in age, gender, pseudophakia were observed between the groups. There was no significant difference in HbA1c value among the three diabetic groups. Mean foveal choroidal thickness was 270.09 ± 42.41 in NDR group, 243.18 ± 30.21 in DR/ME? group and 250.90 ± 40.06 in DR/ME+ group. Mean foveal choroidal thickness in NDR group was significantly different from DR/ME? group. There was no statistically significant difference between the other groups among foveal choroidal thicknesses. There was no correlation between HbA1c and foveal choroidal thickness. Multiple regression analyses of two diabetic retinopathy groups showed no significant correlation between foveal choroidal thickness and HbA1c and also no significant correlation between foveal choroidal thickness and duration of diabetes.

Conclusions

Serum HbA1c levels were not correlated with foveal choroidal thickness. Choroidal thickness is effected by several factors as axial length, age and systemic diseases.