Optical system based on time-gated, intensified charge-coupled device camera for brain imaging studies

An imaging system for brain oxygenation based on a time-gated, intensified charge-coupled device camera was developed. It allows one to image diffusely reflected light from an investigated medium at defined time windows delayed with respect to the laser pulse. Applying a fast optomechanical switch to deliver the light at a wavelength of 780 nm to nine source fibers allowed one to acquire images in times as short as 4 s. Thus, the system can be applied in in vivo studies. The system was validated in phantom experiments, in which absorbing inclusions were localized at different depths and different lateral positions. Then, the decrease in absorption of the brain tissue related to increase in oxygenation was visualized in the motor cortex area during finger tapping by a healthy volunteer.     

Cytoskeletal Disassembly and Cell Rounding Promotes Adipogenesis from ES Cells

Biomechanical signals such as cell shape and spreading play an important role in controlling stem cell commitment. Cell shape, adhesion and spreading are also affected by calreticulin, a multifunctional calcium-binding protein, which influences several cellular processes, including adipogenesis. Here we show that cytoskeletal disruption in mouse embryonic stem cells using cytochalasin D or nocodazole promotes adipogenesis. While cytochalasin D disrupts stress fibres and inhibits focal adhesion formation, nocodazole depolymerises microtubules and promotes focal adhesion formation. Furthermore, cytochalasin D increases the levels of both total and activated calcium/calmodulin-dependent protein kinase II, whereas nocodazole decreases it. Nevertheless, both treatments significantly increase the adipogenic potential of embryonic stem cells in vitro. Both cytochalasin D and nocodazole exposure caused cell rounding suggesting that it is cell shape that causes the switch towards the adipogenic programme. Calreticulin-containing embryonic stem cells, under baseline conditions, show low adipogenic potential, have low activity of signalling via calcium/calmodulin-dependent protein kinase II and display normal adhesive properties and cellular spreading in comparison to the highly adipogenic but poorly spread calreticulin-deficient ES cells. We conclude that forced cell rounding via cytoskeletal disruption overrides the effects of calreticulin, an ER chaperone, thus negatively regulating adipogenesis via focal adhesion-mediated cell spreading.     

Mucinous tubular and spindle-cell carcinoma of the kidney

4 cases (2 males and 2 females) of mucinous tubular and spindle-cell carcinoma of the kidney were studied. The patients' age was 43 to 87 years. Microscopically, this tumor comprised two major cell populations. One of them involved spindle cells with a sparse cytoplasm, which were arranged in the fascicular pattern, often resembling low-grade smooth muscle tumors. The other population was small cuboidal cells with round nuclei and an eosinophilic cytoplasm. The mitotic activity was low. Only one tumor had both cell components. The other three tumors were represented by the second type cells. Immunohistochemical staining with avidin-biotin was performed by using cytokeratin, vimentin, SMA, p53, Bcl 2, EMA, and CD10. All cases were stained positively with antibodies to the cytokeratins AE1-AE2 and vimentin. The expression of EMA, Bcl 2, and CK7 was varying in different tumors. Responses to smooth muscle actin, p53, CK20, and CD10 were negative in all cases. Mucinous tubular and spindle-cell carcinoma of the kidney should be differentiated from angiomyolipoma with the preponderance of a leiomyomatous component, renal smooth muscle neoplasms, metanephrotic adenoma, and renal cell carcinoma with sarcomatoid differentiation.     

Chromophobe renal cell carcinoma with liposarcomatous dedifferentiation - report of a unique case

Sarcomatous transformation of chromophobe renal cell carcinoma (CRCC) is a well recognized phenomenon. Of the published cases with sarcomatous transformation of CRCC, none have shown liposarcomatous differentiation. Out of a cohort of 250 cases of CRCC, 19 (7.6%) showed sarcomatous differentiation. In one case (female, age 46 years), the sarcomatous component of the tumor displayed histological features of a pleomorphic liposar-coma. Light microscopic examination revealed a biphasic pattern with a chromophobe renal cell carcinoma(CRCC) and a high-grade sarcomatous component containing large pleomorphic lipoblasts. In several areas both components were intermingled. The conventional CRCC component showed classic histological features with calcifications, medium-sized polygonal cells arranged in solid-alveolar structures with raisinoid nuclei, pale-eosinophilic flocculent cytoplasm with perinuclear haloes. In addition, a microcystic-adenomatous component had luminal spaces filled with erythrocytes. The CRCC was positive with Hale''s colloidal iron-stain whereas the sarcomatous component was negative. The CRCC component was diffusely positive for cytokeratin 7, parvalbumin and racemase but negative for cy-tokeratin 20, vimentin, CD10, carboanhydrase IX and S100-protein. The pleomorphic liposarcomatous component displayed immunereactivity for CD10, vimentin, racemase and focally for carboanhydrase IX. The proliferative activity (Mib-1/Ki-67) was 5% in the CRCC and 30% in the pleomorphic liposarcomatous component. No immunereactivity for MDM2 or CDK4 was detected.This is the first reported case of a sarcomatoid CRCC where the sarcomatous component displayed features of a pleomorphic liposarcoma. The patient died from widespread metastatic disease 12 months after nephrectomy.     

Intraoperative imprint cytology of central neurocytoma: The great oligodendroglioma mimicker

Intraoperative cytologic evaluation of brain tumors has been used either to render a preliminary interpretation or more often as a complement to frozen section examination. Central neurocytoma is a intraventricular neoplasm, typically located in the region of the foramen of Monro, affecting mostly young to middle age adults. Histologically, central neurocytomas are characterized by monotonous cells with round nuclei and neuronal differentiation within a rich capillary network. Their distinction during intraoperative consultations from oligodendroglioma, ependymoma (mainly clear cell ependymoma), and non‐Hodgkin lymphoma can be a diagnostic challenge. We report a case of a 19‐year‐old female with an intraventricular tumor where imprint cytology preparations were crucial for the intraoperative diagnosis of central neurocytoma. Imprint cytology preparations show a round cell neoplasm associated with neuropil clumps and short straight capillaries admixed with tumor cell clusters. To the best of our knowledge, only a few cases describing the cytologic findings of central neurocytomas have been reported in the medical literature. The differential diagnosis, tissue correlation, clinical‐radiologic features, and ancillary studies are discussed. Diagn. Cytopathol. 2010. © 2009 Wiley‐Liss, Inc.     

Pregnancy outcome after age 50

OBJECTIVE: To evaluate pregnancy complications occurring after age 50. METHODS: We compared the pregnancy outcomes of women aged 50-64 years with those aged 45-49 years and with the general population. RESULTS: During 5 years from January 1, 1999, to June 30, 2004, 123 women aged 45 years and older gave birth. Fifty-five percent were nulliparous, 24 of 123 were aged 50-64 years, and 99 of 123 women were aged 45-49 years. All women older than age 50 conceived via in vitro fertilization with oocyte donation. For these 123 women, the overall mean gestational age at delivery was 37.6+/-2.6 weeks. The mean birth weight was 2,684+/-754 g, significantly lower than the general population, and the incidences of multifetal pregnancies, diabetes, and hypertension were high. Women aged 50 years and older were more likely to be hospitalized during pregnancy than women younger than 50 years (63% versus 22%, P<.001). Neonatal outcome was generally good. Women aged 50 years and older gave birth to significantly more low birth weight babies than those younger than age 50 years (61% versus 32%, P=.002). Gestational age and birth weight were both significantly lower for singletons and multiples in women older than age 50 years compared with those younger than age 50 years (gestational age of singletons 36.9 versus 38.4 weeks, P=.005; birth weight of singletons 2,694 versus 3,027 g, P=.019; gestational age of multiples 35.1 versus 36.4 weeks, P=.01; birth weight of multiples 1,976 versus 2,310 g, P=.038, respectively). CONCLUSION: Pregnant women aged 50-64 years have increased risks of preterm birth, low birth weight babies, diabetes mellitus, hypertension, and hospitalization. LEVEL OF EVIDENCE: II-2.