T2 laryngeal cancer study in our department

Laryngeal cancer is the most common malignant tumor in the head and neck region.Because early detection and treatment are possible, outcomes are relatively good.Many studies have reported on the treatment of laryngeal cancer.Different hospitals have used generally similar treatment regimens.However, factors such as laryngeal preservation and the treatment of choice for patients with T2 laryngeal cancer still differ among hospitals.Survival rates can be increased depending on treatment, sometimes at the cost of losing voice functions that could have been preserved.In our department, we have emphasized curative treatment and the preservation of organs and functions.We have mainly used chemoradiotherapy concurrently with S-1 and nedaplatin for the treatment of T2 laryngeal cancer.We studied 27 patients(23 men and 4 women)with T2 laryngeal cancer, who received first-line therapy in our department from April 2005 through March 2010. Their mean age was 64.1 years(range, 42 to 80).The mean follow-up period was 30.6 months(range, 2 to 60 months).The tumor-nodemetastasis classification was T2N0M0 in 24 patients, T2N1M0 in 1, and T2N2bM0 in 2.In our department, the disease-specific survival rate was 96.3%. The complete response rate was 88.9%, and the laryngeal preservation rate was 92.6%.     

Paragonimiasis in a person whose symptoms were shown 22 years after emigrating to Japan from Laos

We report a patient, a 52-year-old man from Laos, who had come to Japan at 30 years of age, but had maintained a habit of eating raw freshwater crabs. The patient visited a physician for left chest pain in January 2007. Infiltration and mass-like shadows were noted in the left superior and inferior lobes on chest X-ray. Diagnosis could not be made by bronchial brushing, but eggs were present in sputum cytology 3 days after bronchoscopy. Therefore, paragonimiasis was diagnosed. The peripheral eosinophil count had increased to 2550/μl and the serum IgE level was elevated, at 71000 IU/ml. Multiple-dot enzyme-linked immunosorbent assay (ELISA) for specific IgG antibodies in serum was positive for Paragonimus westermani and P. miyazakii. Paragonimiasis may have been caused by the style of Laotian cooking without heating. Because the habit of eating raw freshwater crabs is common in Laos, Laos is one of the countries where paragonimiasis is prevalent. For patients from Laos with lung diseases, differentiation including paragonimiasis is required.     

Dok-1 and Dok-2 are negative regulators of T cell receptor signaling

Interaction of the TCR complex with self- or foreign peptides is a central event in the immune responses. Upon TCR stimulation, a protein-tyrosine kinase (PTK), ZAP-70, is recruited to signaling units of the TCR complex, such as TCRzeta, to play an essential role in T cell activation. Here, we find that mice lacking adaptor proteins Dok-1 and Dok-2 show augmented responses to thymus-dependent, but not thymus-independent, antigens, and that their T cells show elevated responses to TCR stimulation, including the activation of ZAP-70 and subsequent proliferation and cytokine production. Furthermore, the forced expression of Dok-1 or Dok-2 in a CD3(+)CD4(+) T cell clone inhibited the activation of ZAP-70 upon TCR stimulation. Interestingly, the Dok-1 and Dok-2 COOH-terminal moieties bearing the src homology 2 target motifs were dispensable for this negative regulation, even though they are crucial for the known adaptor function of Dok-family proteins. Thus, by an as yet unidentified mechanism, Dok-1 and Dok-2 play an essential role in the negative regulation of TCR signaling. Consistently, all mice lacking these proteins exhibited elevated titers of antibodies to double-stranded DNA and developed lupus-like renal disease.     

Selection of reliable reference genes for the normalisation of gene expression levels following time course LPS stimulation of murine bone marrow derived macrophages

Background

Macrophages are key players in the initiation, perpetuation and regulation of both innate and adaptive immune responses. They largely perform these roles through modulation of the expression of genes, especially those encoding cytokines. Murine bone marrow derived macrophages (BMDMs) are commonly used as a model macrophage population for the study of immune responses to pro-inflammatory stimuli, notably lipopolysaccharide (LPS), which may be pertinent to the human situation. Evaluation of the temporal responses of LPS stimulated macrophages is widely conducted via the measurement of gene expression levels by RT-qPCR. While providing a robust and sensitive measure of gene expression levels, RT-qPCR relies on the normalisation of gene expression data to a stably expressed reference gene. Generally, a normalisation gene(s) is selected from a list of “traditional” reference genes without validation of expression stability under the specific experimental conditions of the study. In the absence of such validation, and given that many studies use only a single reference gene, the reliability of data is questionable.

Results

The stability of expression levels of eight commonly used reference genes was assessed during the peak (6 h) and resolution (24 h) phases of the BMDM response to LPS. Further, this study identified two additional genes, which have not previously been described as reference genes, and the stability of their expression levels during the same phases of the inflammatory response were validated. Importantly, this study demonstrates that certain “traditional” reference genes are in fact regulated by LPS exposure, and, therefore, are not reliable candidates as their inclusion may compromise the accuracy of data interpretation. Testament to this, this study shows that the normalisation of gene expression data using an unstable reference gene greatly affects the experimental data obtained, and, therefore, the ultimate biological conclusions drawn.

Conclusion

This study reaffirms the importance of validating reference gene stability for individual experimental conditions. Given that gene expression levels in LPS stimulated macrophages is routinely used to infer biological phenomena that are of relevance to human conditions, verification of reference gene expression stability is crucial.

     

Nonfunction of the ECT2 gene may cause renal tubulointerstitial injury leading to focal segmental glomerulosclerosis

Background

Secondary focal segmental glomerulosclerosis (FSGS) follows congenital or acquired tubulointerstitial alterations such as in Dent??s disease, Lowe syndrome, and reflux nephropathy. Failure of adequate regeneration after tubulointerstitial injury, or abnormal tubulogenesis, can disturb intrarenal blood circulation, causing excessive glomerular filtration. The epithelial cell-transforming sequence 2 gene (ECT2) contributes to tight junction function in epithelial cells.

Methods

We encountered two patients with a nonfunctioning ECT2 genotype who later developed FSGS. Both developed proteinuria associated with acute renal failure in early childhood.

Results

Renal biopsy specimens showed marked tubulointerstitial nephritis at the onset of proteinuria, later progressing to FSGS consequent to tubulointerstitial injury. The patients did not respond to corticosteroids and attained only incomplete remission upon cyclosporine A administration. One patient received a maternal renal transplant with good function and no rejection.

Conclusions

ECT2 is important for tight junction function and maintenance of cell polarity. Nonfunction of this gene may cause renal tubulointerstitial injury, progressing to glomerular sclerosis.     

Short-term effect of bezafibrate on the expression of adiponectin mRNA in the adipose tissues: a study in spontaneously type 2 diabetic rats with visceral obesity

The effect of short-term bezafibrate (BF) administration over time on the expression of adiponectin mRNA in the tissues was examined in Otsuka Long Evans Tokushima Fatty (OLETF) rats. Eight-week-old rats were divided into the high-dose (100 mg/kg) BF group (n=15), the low-dose (10 mg/kg) BF group (n=15), or the control group (n=15) and followed up for 14 d. Triglyceride and free fatty acid levels significantly decreased in a dose-dependent manner in the high-dose BF group. The insulin levels increased with time, although they were significantly lower in the high-dose BF group on d 3 and 7 than the control group. Adiponectin levels significantly increased in the high-dose BF group. On d 14 of BF administration, the levels of VLDL and chylomicron were significantly lower in BF groups, and adiponectin mRNA expression in the white adipose tissue was significantly higher in the high-dose BF group. Findings from this study suggest that in type 2 diabetes with insulin resistance, hypertriglyceridemia is closely linked to adiponectin.     

Characterization of neuropeptide Y (NPY) Y5 receptor-mediated obesity in mice: chronic intracerebroventricular infusion of D-Trp(34)NPY

To clarify the role of the neuropeptide Y (NPY) Y5 receptor subtype in energy homeostasis, the effect of the intracerebroventricular infusion of a selective Y5 agonist, D-Trp(34)NPY, was investigated in C57BL/6J mice. Intracerebroventricular infusion of D-Trp(34)NPY (5 and 10 microg/d) produced hyperphagia and body weight gain, accompanied by increased adipose tissue weight, hypercholesterolemia, hyperinsulinemia, and hyperleptinemia. Oral administration of a selective Y5 antagonist at a dose of 100 mg/kg twice a day completely suppressed all of these D-Trp(34)NPY-induced changes, indicating that chronic activation of the Y5 receptor produces hyperphagia and obesity. In addition, D-Trp(34)NPY still resulted in an increase in adipose tissue weight accompanied by hyperleptinemia and hypercholesterolemia, although D-Trp(34)NPY-induced food intake was restricted by pair-feeding. Under the pair-fed condition, D-Trp(34)NPY decreased hormone-sensitive lipase activity in white adipose tissue and uncoupling protein-1 mRNA expression in brown adipose tissue. These findings indicate that Y5-mediated obesity may involve metabolic changes, such as decreased lipolysis and thermogenesis, as well as hyperphagia. Therefore, the Y5 receptor can play a key role in regulating energy homeostasis.     

Measuring collective transport by defined numbers of processive and nonprocessive kinesin motors

Intracellular transport is thought to be achieved by teams of motor proteins bound to a cargo. However, the coordination within a team remains poorly understood as a result of the experimental difficulty in controlling the number and composition of motors. Here, we developed an experimental system that links together defined numbers of motors with defined spacing on a DNA scaffold. By using this system, we linked multiple molecules of two different types of kinesin motors, processive kinesin-1 or nonprocessive Ncd (kinesin-14), in vitro. Both types of kinesins markedly increased their processivities with motor number. Remarkably, despite the poor processivity of individual Ncd motors, the coupling of two Ncd motors enables processive movement for more than 1 μm along microtubules (MTs). This improvement was further enhanced with decreasing spacing between motors. Force measurements revealed that the force generated by groups of Ncd is additive when two to four Ncd motors work together, which is much larger than that generated by single motors. By contrast, the force of multiple kinesin-1s depends only weakly on motor number. Numerical simulations and single-molecule unbinding measurements suggest that this additive nature of the force exerted by Ncd relies on fast MT binding kinetics and the large drag force of individual Ncd motors. These features would enable small groups of Ncd motors to crosslink MTs while rapidly modulating their force by forming clusters. Thus, our experimental system may provide a platform to study the collective behavior of motor proteins from the bottom up.