Sarcopenic Dysphagia and Simplified Rehabilitation Nutrition Care Process: An Update

Sarcopenic dysphagia is characterized by weakness of swallowing-related muscles associated with whole-body sarcopenia. As the number of patients with sarcopenia increases with the aging of the world, the number of patients with sarcopenic dysphagia is also increasing. The prevalence of sarcopenic dysphagia is high in the institutionalized older people and in patients hospitalized for pneumonia with dysphagia in acute care hospitals. Prevention, early detection and intervention of sarcopenic dysphagia with rehabilitation nutrition are essential. The diagnosis of sarcopenic dysphagia is based on skeletal and swallowing muscle strength and muscle mass. A reliable and validated diagnostic algorithm for sarcopenic dysphagia is used. Sarcopenic dysphagia is associated with malnutrition, which leads to mortality and Activities of Daily Living (ADL) decline. The rehabilitation nutrition approach improves swallowing function, nutrition status, and ADL. A combination of aggressive nutrition therapy to improve nutrition status, dysphagia rehabilitation, physical therapy, and other interventions can be effective for sarcopenic dysphagia. The rehabilitation nutrition care process is used to assess and problem solve the patient's pathology, sarcopenia, and nutrition status. The simplified rehabilitation nutrition care process consists of a nutrition cycle and a rehabilitation cycle, each with five steps: assessment, diagnosis, goal setting, intervention, and monitoring. Nutrition professionals and teams implement the nutrition cycle. Rehabilitation professionals and teams implement the rehabilitation cycle. Both cycles should be done simultaneously. The nutrition diagnosis of undernutrition, overnutrition/obesity, sarcopenia, and goal setting of rehabilitation and body weight are implemented collaboratively.

Incidence and possible pathogenesis of sentinel node micrometastases in ductal carcinoma in situ of the breast detected using molecular whole lymph node assay

Background:

The pathogenesis of lymph node metastases in preinvasive breast cancer – ductal carcinoma in situ (DCIS) – remains controversial. The one-step nucleic acid amplification (OSNA) assay is a novel molecular method that can assess a whole node and detect clinically relevant metastases. In this retrospective cohort study, we determined the performance of the OSNA assay in DCIS and the pathogenesis of node-positive DCIS.

Methods:

The subjects consisted of 623 patients with DCIS who underwent sentinel lymph node (SN) biopsy. Of these, 2-mm-sectioned nodes were examined using frozen-section (FS) histology in 338 patients between 2007 and 2009, while 285 underwent OSNA whole node assays between 2009 and 2011. The SN-positivity rate was compared between cohorts, and the characteristics of OSNA-positive DCIS were investigated.

Results:

The OSNA detected more cases of SN metastases than FS histology (12 out of 285, 4.2% vs 1 out of 338, 0.3%). Most of the metastases were micrometastases. The characteristics of high-risk DCIS (i.e., mass formation, size, grade, and comedo) and preoperative breast biopsy (i.e., methods or time to surgery) were not valid for OSNA assay–positive DCIS.

Conclusion:

The OSNA detects more SN metastases in DCIS than FS histology. Further examination of the primary tumours and follow-up of node-positive DCIS are needed to elucidate the pathogenesis.

The response to neoadjuvant chemotherapy and prognosis of triple-negative breast cancer patients

Abstract #5121

Purpose: It is said that triple negative breast cancer (TNBC) has poor prognosis. However, many study shows TNBC has better response to chemotherapy. Since neoadjuvant chemotherapy plays an important role to TNBC, we compared clinical and pathological response rate and prognosis between TNBC and non-TNBC.
 Patients and methods: This analysis retrospectively collected 2563 breast cancer patients for StageI-III who underwent surgery between January 2000 and September 2004 (median: 3.9 years) at National Cancer Center, Tokyo, Japan. We defined TNBC as Estorpgen and progesterone receptor negative and HER2 score 0-2+ by immnohistological report. There were 91 TNBC patients (23.1%) out of 400 patients (15.6%) who underwent neoadjuvant chemotherapy. Clinical and pathological response rate and Four-year progression free survival were compared between TNBC and non-TNBC.
 Results: There were 91 TNBC patients (23.1%). TNBC patients compared with non-TNBC had tendency to achieve cCR (91% vs 78%; p=.058) although TNBC had higher rate for cPD (6.6% vs 1.7%; p <.0001). Also TNBC tended to have higher pathological CR rate of which we classified pCR only for grade 3 cases, compared to non-TNBC (13.1% vs 7.2%; p= .042 ). Interestingly HER2 overexpression type also had higher rate for pCR. As for pPD rate, TNBC had similar rate compared to non-TNBC (5.5% v 4.3%). Four-year progression free- survival rate was higher for non-TNBC. However, TNBC had higher Four-year survival free rate only when pCR were achieved after neoadjuvant chemotherapy (99% vs 82%; p=.02).
 Conclusion: Patients with TNBC tend to have clinical and pathological response of either CR or PD. Although non-TNBC had better prognosis by four-year survival free rate, TNBC could have better prognosis if neoadjuvant chemotherapy resulted in pCR. There may be some way to predict the efficacy of neoadjuvant chemotherapy and prognosis by analyzing the shrink pattern.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5121.

Mutation induction by heavy-ion irradiation of gpt delta transgenic mice

Using the new transgenic mice produced by mating gpt delta with p53 knockout, mutation induction by heavy-ion irradiation and the effect of p53 background on such induction were studied. After the whole body irradiation with 10 Gy of 135 MeV/u carbon-ion beam, the genomic DNA was isolated from the different organs and the lambda DNA was rescued as a phage. Mutations in the transgene on the lambda DNA were determined by the spi(-) selection (deletion assay). The spi(-) mutation was induced by the above irradiation, but enhancement of the mutant frequency by the knockout of p53 gene was found not in the phages recovered from liver but in those from kidney. We are now making an effort to determine the nature of spi(-) mutation to confirm such p53 effect.

Reporter gene transgenic mice as a tool for analyzing the molecular mechanisms underlying experimental carcinogenesis

Carcinogenic compounds are classified into 2 categories, genotoxic and non-genotoxic, which are basically judged from in vitro genotoxicity data. However, it is well documented that genotoxicants do not necessarily exert in vivo carcinogenicity in rodents, partly because of a discrepancy between in vitro and in vivo mutagenicities. Recently, transgenic animal models with reporter genes such as lacI, lacZ and gpt have been developed as a tool for assessing in vivo mutagenicity as well as carcinogenicity. In this article, data using lacI transgenic mice and gpt delta mice are presented and their application is discussed. In lacI transgenic mice, dimethylnitrosamine (DMN) treatment significantly increased lacI mutant frequency (MF) in the liver, kidenys and lungs, but not in other non-target organs. Repeated dose ip administration of DMN was more effective than single dose treatment in the induction of lacI MF. The spectrum of mutant plaques induced by DMN was characterized by deletions as well as GC to AT base transitions. The remaining mice receiving DMN proved to have liver adenomas at a high frequency after 78 weeks. Meanwhile, dietary 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MelQx) significantly increased lacI and gpt MFs in the liver and colon. The characteristic spectrum of mutant plaques induced by MeIQx was a GC to TA base transversion in both the lacI and gpt mutations. Our results thus strongly suggest that these reporter gene transgenic animal models could offer a useful tool for analyzing molecular mechanisms underlying experimental carcinogenesis and for assessing the carcinogenic risk of environmental chemicals.

Recent advances in the protocols of transgenic mouse mutation assays

Transgenic mutation assays were developed to detect gene mutations in multiple organs of mice or rats. The assays permit (1) quantitative measurements of mutation frequencies in all tissues/organs including germ cells and (2) molecular analysis of induced and spontaneous mutations by DNA sequencing analysis. The protocols of recently developed selections in the lambda phage-based transgenic mutation assays, i.e. cII, Spi(-) and 6-thioguanine selections, are described, and a data set of transgenic mutation assays, including those using Big Blue and Muta Mouse, is presented.

Characterization of mutations induced by 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine in the colon of gpt delta transgenic mouse: novel G:C deletions beside runs of identical bases

Mutations induced by one of the typical dietary mutagens/carcinogens, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), were characterized using gpt delta transgenic mice. This transgenic mouse model has two selection methods to efficiently detect different types of mutations, i.e. 6-thioguanine selection for point mutations and Spi(-) selection for deletions. The mice were fed with a diet containing 400 p.p.m. PhIP for 13 weeks and gpt and Spi(-) mutations were analyzed from the colon, where the highest mutant frequencies were detected. Concerning the types of gpt mutations from PhIP-treated mice, 81% were single base pair substitutions and G:C-->T:A transversions predominated; single base pair deletions at G:C base pairs were also observed. In untreated mice G:C-->A:T transitions predominated and >80% of these events involved 5'-CpG-3' sites. Concerning Spi(-) mutants from PhIP-treated mice, 76% were G:C base pair deletions and more than half of these events occurred in monotonic G or C run sequences. Interestingly, a novel type of frameshift motif, i.e. G:C base pair deletions beside run sequences, was observed. The most frequently observed mutation in this class was the 5'-TTTTTTG-3'-->5'-TTTTTT-3' event. These results suggest that PhIP induces point mutations, such as base substitutions and single base pair deletions, rather than larger deletions in vivo and that run sequences may play an important role in PhIP-induced G:C base pair deletions.

Mutation induction by heavy ion irradiation of gpt delta transgenic mice

Using the new transgenic mice produced by mating gpt delta with p53 knockout, mutation induction by heavy-ion irradiation and the effect of p53 background on such induction were studied. After the whole body irradiation with 10 Gy of 135 MeV/u carbon-ion beam, the genomic DNA was isolated from the different organs and the lambda DNA was rescued as a lambda phage. Mutations in the transgene on the lambda DNA were determined by the spi(-) selection (deletion assay). The spi(-) mutation was induced by the above irradiation, but enhancement of the mutant frequency by the knockout of p53 gene was found not in the phages recovered from liver but in those from kidney. We are now making an effort to determine the nature of spi(-) mutation to confirm such p53 effect.

Mmh/Ogg1 gene inactivation results in accumulation of 8-hydroxyguanine in mice

The major mutagenic base lesion in DNA caused by exposure to reactive oxygen species is 8-hydroxyguanine or 7, 8-dihydro-8-oxoguanine (8-OH-G). Products of the human MMH/OGG1 gene are known to catalyze in vitro the reactions repairing this DNA lesion. To analyze the function of Mmh in vivo, we generated a mouse line carrying a mutant Mmh allele by targeted gene disruption. Mmh homozygous mutant mice were found to have a physically normal appearance, but to have lost nicking activity in liver extracts for substrate DNA containing 8-OH-G, exhibiting a 3-fold increased accumulation of this adduct at 9 weeks of age compared with wild-type or heterozygous mice. Further elevation to 7-fold was observed in 14-week-old animals. Substantial increase of spontaneous mutation frequencies was clearly identified in Mmh mutant mice bearing transgenic gpt genes. These results indicate that exposure of DNA to endogenous oxidative species continuously produces the mutagenic adduct 8-OH-G in mice, and Mmh plays an essential role in repair of this DNA damage.

Mutagenicity of 2-amino-1-methyl-6-phenylimidazo [4,5-b]pyridine (PhIP) in the new gpt delta transgenic mouse

Gender differences and organ specificity of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)-induced mutagenesis were examined with the new gptdelta transgenic mouse (T. Nohmi, M. Katoh, H. Suzuki, M. Matsui, M. Yamada, M. Watanabe, M. Suzuki, N. Horiya, O. Ueda, T. Shibuya, H. Ikeda, T. Sofuni, A new transgenic mouse mutagenesis test system using Spi-and 6-thioguanine selections (Environ. Mol. Mutagen. 28 (1996) 465-470). In this mouse model, two distinct selections are employed to efficiently detect different types of mutations, i.e 6-thioguanine (6-TG) selection for point mutations and Spi-selection for deletions, respectively. In both selections, the highest mutant frequencies were observed in colon, followed by in spleen and liver. No increases in mutations were observed in testis, brain and bone marrow in PhIP-treated male mice. No significant differences in 6-TG and Spi- mutant frequencies were observed in colon and liver between male and female treated mice. The correlation between PhIP-induced mutagenesis and carcinogenesis in colon is discussed.

UVB-induced gpt mutations in the skin of gpt delta transgenic mice

Ultraviolet light B (UVB)-induced mutagenesis was studied in gpt delta transgenic mice, which contain the lambdaEG10 shuttle vector as a transgene. The mice were exposed to UVB at single doses of 0.3, 0.5, 1.0, 1.5, and 2.0 kJ/m(2). At 4 weeks after irradiation, the mutant frequencies (MF) of the gpt gene were determined in the epidermis and the dermis, and the gpt mutations in the epidermis were identified by DNA sequencing. The epidermis exhibited a higher sensitivity to UVB than the dermis at doses of 0.3 and 0.5 kJ/m(2) UVB: the MF of the epidermis were more than nine times higher than those of the nonirradiated mice, whereas the MF of the dermis were only two to three times higher than the nonirradiated level at the doses used. The UVB-induced mutation spectrum in the epidermis was dominated by G:C to A:T transitions at dipyrimidine sites, such as 5'-TC-3', 5'-CC-3', and 5'-T/C-CG-3'. Tandem transitions such as CC to TT were also observed. Interestingly, a remarkable bias towards the template strand of the gpt gene was observed in the single transitions at 5'-TC-3' and 5'-CC-3' sites, but not at 5'-T/C-CG-3' site. In contrast, G:C to A:T transitions at CpG sites and deletions were observed in nonirradiated mice. Hot spots of transitions were observed at different sites in UVB-irradiated and nonirradiated mice. These results indicate that gpt delta transgenic mouse is a suitable model for studying in vivo UVB-induced mutations at the molecular level.

Efficient detection of deletions induced by a single treatment of mitomycin C in transgenic mouse gpt delta using the Spi(-) selection

Transgenic rodent mutation assays permit the detection and molecular analysis of various types of gene mutations, such as base changes and frameshifts, in a number of tissues. It is reported, however, that deletion mutations are not efficiently detected by the assays, in particular those using lambda phage shuttle vectors. Recently, a new transgenic mouse model, i.e., gpt delta, has been developed to selectively detect some types of deletions by Spi(-) selection. Spi(-) selection has an advantage over the other selections to preferentially identify deletions because only lambda phages deficient in both the red and gam gene functions are allowed to form phage plaques. In this study, we examined whether in vivo deletions induced by the treatment of mitomycin C (MMC) are detectable by the Spi(-) assay in the mouse model. The mice were treated with MMC (0.5, 1.0, 2.0, and 4.0 mg/kg, single intraperitoneal injection) and sacrificed 14 days after the dosing. The treatment at 4.0 mg/kg approximately doubled the mutant frequency of Spi(-) in the bone marrow, i.e., 2.52 x 10(-6) vs. 1.31 x 10(-6). The molecular analyses using polymerase chain reaction (PCR) and DNA sequencing indicated that seven Spi(-) mutants at 4.0 mg/kg group had deletions with molecular sizes from 0.8 kilo basepairs (kb) to 8.5 kb, whereas no such deletions were observed in the Spi(-) mutants in the control group. The results suggest that deletions induced by MMC in the bone marrow are efficiently detectable by Spi(-) selection and also that the molecular analyses are useful to evaluate the significance of a marginal increase in mutant frequency in the transgenic rodent mutation assays.

Spectra of gpt mutations in ethylnitrosourea-treated and untreated transgenic mice

We have established a new transgenic mouse mutagenicity assay for the efficient detection of point mutations and deletions in vivo (Nohmi et al. [1996] Env. Mol. Mutagen. 28:465-470). In this assay, the gpt gene of Escherichia coli is used as a reporter for the detection of point mutations. Treatment of mice with ethylnitrosourea (ENU, 150 mg/kg) enhances by several-fold the mutant frequency of gpt in bone marrow. Here, we report the mutation spectra of the gpt gene recovered from bone marrow of ENU-treated and untreated transgenic mice. In the gpt mutants rescued from ENU-treated mice, more than 90% of the mutations were base change mutations; the predominant types were A:T to T:A transversions and G:C to A:T transitions. On the contrary, in the mutants rescued from untreated mice, 54% were base substitutions and the remainders were short deletions and insertions. Among untreated mice, the most frequently observed base substitution was G:C to A:T transitions (7/14 mutants). Three of these occurred at 5'-CpG-3' sites. Interestingly, the mutation spectra of the gpt gene were different from those of the gpt gene in ENU-treated and untreated E.coli, whereas they were similar to those of the lacZ and lacI genes in ENU-treated and untreated other transgenic mice or cultured mammalian cells. We also report the establishment of homozygous transgenic mice that have transgene lambdaEG10 DNA in both chromosome 17 of C57BL/6J mouse.

Spi(-) selection: An efficient method to detect gamma-ray-induced deletions in transgenic mice

Despite the importance of genome rearrangement in the etiology of cancer and human genetic disease, deletion mutations are poorly detectable by transgenic rodent mutagenicity tests. To facilitate the detection and molecular analysis of deletion mutations in vivo, we established a transgenic mouse model harboring a lambdaEG10 shuttle vector that includes the red and gam genes for Spi(-) (sensitive to P2 interference) selection [Nohmi et al. (1996] Environ. Mol. Mutagen. 28:465-470]. This selection has a great advantage over other genetic systems, because phage deletion mutants can be preferentially selected as Spi(-) plaques, which can then be subjected to molecular analysis. Here, we show nucleotide sequences of 41 junctions of deletion mutations induced by gamma-irradiation. Unlike spontaneous deletion mutants, more than half of the large deletions occurred between short homologous sequences from one to eight bp. The remaining junctions had no such homologous sequences. Intriguingly, two Spi(-) mutants had P (palindrome)-like nucleotide additions at the breakpoints, which are frequently observed in the coding junctions of V(D)J recombination, suggesting that broken DNA molecules with hairpin structures can be intermediates in the repair of radiation-induced double-strand breaks. We conclude that Spi(-) selection is useful for the efficient detection of deletion mutations in vivo and that most rearrangements induced by gamma-rays in mice are mediated by illegitimate recombination through DNA end-joining.