86 research outputs found
Regulation of murine cytochrome c oxidase Vb gene expression during myogenesis: YY-1 and heterogeneous nuclear ribonucleoprotein D-like protein (JKTBP1) reciprocally regulate transcription activity by physical interaction with the BERF-1/ZBP-89 factor.
A transcription suppressor element (sequence -481 to -320) containing a G-rich motif (designated GTG) and a newly identified CAT-rich motif (designated CATR) was previously shown to modulate expression of the mouse cytochrome c oxidase Vb gene during myogenesis. Here, we show that the GTG element is critical for transcription activation in both undifferentiated and differentiated myocytes. Mutations of the CATR motif abolished transcription repression in myoblasts while limiting transcription activation in differentiated myotubes, suggesting contrasting functional attributes of this DNA motif at different stages of myogenesis. Results show that the activity of the transcription suppressor motif is modulated by an orchestrated interplay between ubiquitous transcription factors: ZBP-89, YY-1, and a member of the heterogeneous nuclear ribonucleoprotein D-like protein (also known as JKTBP1) family. In undifferentiated muscle cells, GTG motif-bound ZBP-89 physically and functionally interacted with CATR motif-bound YY-1 to mediate transcription repression. In differentiated myotubes, heterogeneous nuclear ribonucleoprotein D-like protein/JKTBP1 bound to the CATR motif exclusive of YY-1 and interacted with ZBP-89 in attenuating repressor activity, leading to transcription activation. Our results show a novel mechanism of protein factor switching in transcription regulation of the cytochrome c oxidase Vb gene during myogenesis
Perforated mixed carcinoid-adenocarcinoma in transverse colon and at gastroenterostomy site: case report
Goblet cell carcinoid of the large intestine is a rare neoplasm, usually located in ascending colon and rectum. A 60-year-old male patient underwent surgery after the diagnosis of acute abdomen. Exploratory laparotomy revealed perforation with a diameter of 1 cm at the site of the previously performed gastroenterostomy and dilatation of the right colic flexure, secondary to a solid obstructive mass located in the mid-portion of transverse colon. Histopathological investigation of the biopsies, taken from the gastroenterostomy site and the tumor, revealed mixed carcinoid-adenocarcinoma with carcinoid component, predominantly composed of goblet cells. Three cycles of FOLFOX-4 protocol was administered. Following respiratory distress secondary to pulmonary metastasis, the patient's condition deteriorated and subsequently died in the fourth postoperative month. Our aim with this paper is to point out that more cases should be reported for more effective diagnosis, histopathological study, clinical investigation, treatment and prognosis of this specific neoplasm
Combined adenocarcinoid and mucinous cystadenoma of the appendix: a case report
<p>Abstract</p> <p>Introduction</p> <p>Adenocarcinoid of the appendix is a rare malignant tumour with features of both adenocarcinoma and carcinoid, showing both epithelial and endocrine differentiation. Mucinous cystadenoma is the commonest of the benign neoplasms of the appendix, with an incidence of 0.6% in appendicectomy specimens. We report a rare combination of these tumours and discuss the latest treatment options. To the best of our knowledge, only six cases have been reported in the literature to date.</p> <p>Case presentation</p> <p>A 71-year-old Caucasian man presented to our department with a right iliac fossa mass associated with pain. Laparoscopy revealed an adenocarcinoid of the appendix in combination with mucinous cystadenoma. He underwent a radical right hemicolectomy with clear margins and lymph nodes.</p> <p>Conclusion</p> <p>Adenocarcinoids account for 2% of primary appendiceal malignancies. Most tumours are less than 2 cm in diameter and 20% of them metastasize to the ovaries. The mean age for presentation is 59 years and the 5-year survival rate ranges from 60% to 84%. Right hemicolectomy is generally advised if any of the following features are present: tumours greater than 2 cm, involvement of resection margins, greater than 2 mitoses/10 high-power fields on histology, extension of tumour beyond serosa. Chemotherapy mostly with 5-Fluorouracil and Leucovorin is advised for remnant disease after surgery. Cytoreductive surgery with intraperitoneal chemotherapy can offer improved survival for advanced peritoneal dissemination.</p
Impaired Mitochondrial Respiratory Functions and Oxidative Stress in Streptozotocin-Induced Diabetic Rats
We have previously shown a tissue-specific increase in oxidative stress in the early stages of streptozotocin (STZ)-induced diabetic rats. In this study, we investigated oxidative stress-related long-term complications and mitochondrial dysfunctions in the different tissues of STZ-induced diabetic rats (>15 mM blood glucose for 8 weeks). These animals showed a persistent increase in reactive oxygen and nitrogen species (ROS and RNS, respectively) production. Oxidative protein carbonylation was also increased with the maximum effect observed in the pancreas of diabetic rats. The activities of mitochondrial respiratory enzymes ubiquinol: cytochrome c oxidoreductase (Complex III) and cytochrome c oxidase (Complex IV) were significantly decreased while that of NADH:ubiquinone oxidoreductase (Complex I) and succinate:ubiquinone oxidoreductase (Complex II) were moderately increased in diabetic rats, which was confirmed by the increased expression of the 70 kDa Complex II sub-unit. Mitochondrial matrix aconitase, a ROS sensitive enzyme, was markedly inhibited in the diabetic rat tissues. Increased expression of oxidative stress marker proteins Hsp-70 and HO-1 was also observed along with increased expression of nitric oxide synthase. These results suggest that mitochondrial respiratory complexes may play a critical role in ROS/RNS homeostasis and oxidative stress related changes in type 1 diabetes and may have implications in the etiology of diabetes and its complications
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Work-rest scheduling for manual lifting tasks
The main objectives of this study were: (1) to determine the effects of work-rest ratios on physiological responses for manual lifting tasks performed over different levels of loads and frequencies of lift for a height of lift of 30 from floor level while keeping task duration and work output as constant, (2) to study for a given work period the effect of varied rest periods on energy consumption, (3) to study for a given rest period the effect of varied work periods on energy consumption, and (4) to investigate, for a given work-rest ratio, the effect of short work short rest periods versus long work long rest periods on energy consumption.In order to achieve the objectives of this research, an eloborate experiment was conducted. The independent variables studied were: frequency of lift and work-rest schedules. The response variables for this experiment were: heart rate, oxygen consumption, and minute ventilation.Eight male subjects, 20 to 34 years of age, participated in this experiment. A randomized complete block design with factorial treatment combinations was used. Each subject performed, in a random order, 34 treatment combinations for this experiment. All subjects underwent a training program before the data collection began.The results of this experiment were analyzed using the analysis of variance technique. By manipulating frequency of lift, load, and work-rest ratios whether there could be any significant difference in physiological strain and energy cost for this lifting task with fixed work output for a fixed time at a fixed height of 30 inches above floor level, was tested. It was identified from this experiment that the least work-rest schedule was found to be 12 minutes work followed by 6 minutes rest which was based on the average minimum energy consumption among all the treatments across all the subjects
Ischaemic strictures of the small intestine in Nigeria.
Eleven specimens of small intestinal strictures were seen at the Pathology Department of the University of Benin Teaching Hospital, Benin City, Nigeria, during a period of two and a half years. Eight of them were ischaemic in origin and the clinical and pathological features of these eight cases are described. In five of the cases, the ischaemia could be related to inguinal hernia, with herniorrhaphy a few weeks before surgery for stricture in four cases. The most important factor in making a clinical or pathological diagnosis of ischaemic stricture of the small intestine appears to be awareness of the condition. The importance is emphasised of studying the mesentery, with particular attention to lymph nodes and blood vessels, before making a final diagnosis on intestinal lesions
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