Alterations of repeated sequences in 5' upstream and coding regions in colorectal tumors from patients with hereditary nonpolyposis colorectal cancer and Turcot syndrome

One of the characteristics of tumors from patients with germline mutations of DNA mismatch repair genes is instability at microsatellite regions (MSI). We analysed alterations at repeated sequences of coding regions, as well as those of 5' upstream regions, in 29 MSI-High colorectal tumors from patients with hereditary nonpolyposis colorectal cancer (HNPCC) and Turcot syndrome. We found that repeated sequences in 5' upstream regions were altered in these tumors, at considerable frequencies. The (A)10 repeat in the promoter region (position -178 to approximately -169) of the GAPDH gene was altered in 17% of the tumors. The (A)10(TA)9 in the 5' upstream region (position -318 to approximately -291) of the mitochondrial isoleucyl tRNA synthetase gene (IleRS-A), coded in nuclear DNA, was altered in 59% of the tumors, whereas (A)9 in the 5' upstream region (position -859 to approximately -851) of cytoplasmic isoleucyl tRNA synthetase gene (IleRS-B) was not altered. Alteration at repeated sequences in the coding regions were 72% at TGFbetaRII(A)10, 24% at IGFIIR(G)8, 45% at BAX(G)8, 55% at E2F4(CAG)13, 66% at caspase-5 (A)10, 31% at MBD4(A)10, 55% at hMSH3(A)8 and 34% at hMSH6(C)8. The number of altered genes increased with the advancement of carcinoma according to Dukes categories: mean numbers of altered genes within these 10 genes were 2.6 for Dukes A, 4.7 for Dukes B and 7.8 for Dukes C. The mean number for adenomas was 2.0. These results suggest that the MSI phenotype also causes alteration of 5' upstream regions which may affect apoptosis and some mitochondrial functions in HNPCC and Turcot tumors, and that accumulation of altered genes with repeated sequences is associated with the progression of HNPCC and Turcot colorectal tumors.     

Fusiform and dissecting aneurysm of the vertebrobasilar systems: differential diagnosis

Fusiform aneurysms (FA) and dissecting aneurysms (DA) of the vertebro-basilar systems have been thought to be rare, but recently reports of these aneurysms have increased. The differential diagnosis between FA and DA is requisite for deciding therapy or for prognosis, but it is often difficult to distinguish these aneurysms even if angiographies are conducted. The authors have treated 6 cases with FA and 5 cases with DA during the past 17 years. As the initial symptom, subarachnoid hemorrhage (SAH) was noted in all 6 cases with FA. On the other hand, 2 cases of SAH, 2 cases of brain stem infarction, and 1 case of ischemic attack were noted in DA cases. The aneurysmal locations of FA were at the vertebral artery (VA) in all 6 cases, and those of DA were at the VA in 3 cases and at the basilar artery (BA) in 2 cases. As angiographic findings of DA, pearl & string signs were demonstrated in 3 cases, and retention of contrast medium was noted in 3 cases. Diagnosis of FA is comparatively easy on angiography but when angiospasm exists, it is difficult to differentiate DA from FA. Consequently, repeated angiography is recommended. MR imaging findings of 2 cases with FA were compared with those of 3 cases with DA. No abnormal findings, excepting a dilatation of the signal-void area corresponding to the arterial blood flow were shown in FA, but various abnormalities were detected in all of the 3 cases with DA. Namely, an intimal flap and a double lumen in 1 case, intra-mural hematoma in 1 case, and a hematoma adjacent to the parent artery in 2 cases were demonstrated. Thus, MR imaging was thought to be a useful means for distinguishing between FA and DA.     

Telomere stability is frequently impaired in high-risk groups of patients with myelodysplastic syndromes.

Genomic instability induces an accumulation of genetic changes and may play a role in the pathogenesis of myelodysplastic syndromes (MDS). To clarify the possible association between genomic instability and clinical outcome in MDS patients, we compared telomere dynamics to the recently established International Prognostic Scoring System (IPSS) risk groups for MDS. We measured the terminal restriction fragments (TRFs) of 93 patients with MDS at the time of diagnosis, and telomerase activity was analyzed in 62 patients with MDS using the PCR-based telomeric repeat amplification protocol (TRAP) assay. A total of 53 of 93 MDS patients had TRFs within the age-matched normal range, and the remaining patients showed shortened TRFs (35 patients) or elongated TRFs (5 patients). MDS patients with shortened TRFs had a significantly low hemoglobin concentration (P = 0.04), a high percentage of marrow blasts (P = 0.02), and a high incidence of cytogenetic abnormalities (P < 0.05). The incidence of leukemic transformation was significantly high in patients with shortened TRF length (P < 0.05). In addition, patients with shortened TRF length were frequently seen in the IPSS high-risk group (P < 0.01). Most of the MDS patients had normal-to-low levels of telomerase activity, suggesting that changes in TRF length rather than telomerase activity may more accurately reflect the pathophysiology of MDS. MDS patients with shortened TRF length had a very poor prognosis (P < 0.01), suggesting that telomere dynamics may be linked to clinical outcome in MDS patients. Thus, an abnormal mechanism of telomere maintenance in subgroups of MDS patients may be an early indication of genomic instability. This study demonstrates that telomere stability is frequently impaired in a high-risk group of MDS patients and suggests that, in combination with the IPSS classification system, measurement of TRFs may be useful in the future to stratify MDS patients according to risk and manage the care of MDS patients.     

A case of familial adenomatous polyposis complicated by thyroid carcinoma, carcinoma of the ampulla of vater and adrenocortical adenoma.

A 63 year old female with familial adenomatous polyposis (FAP) complicated by carcinoma of the thyroid and ampulla of Vater and a nonfunctioning adrenocortical adenoma is reported herein. We reviewed 23 cases of duodenal or periampullary carcinoma, 10 cases of thyroid carcinoma and 4 cases of adrenal neoplasm presented in the Japanese literature. From studying these cases, we identified that FAP patients had a high risk of developing periampullary carcinoma and consequently, it is very important to periodically examine the ampulla of Vater. Thyroid carcinomas in patients with FAP were well differentiated carcinomas and occurred earlier than in the general population. The use of medical imaging equipment with mean that insidious abdominal tumors in cases of FAP will be detected more frequently in the future and as patients with FAP have a high risk of developing malignancies, surgery should be indicated for incidentally found adrenal tumors.     

Multipotent and Committed CD34+ Cells in Bone Marrow Transplantation

In order to study the role of CD34⁺ cells in hematological recovery following bone marrow transplantation (BMT), bone marrow cells stained with HPCA-1 (CD34) and MY-9 (CD33) monoclonal antibodies were analyzed by using a fluorescence-activated cell sorter on or about days 14 and 28, as well as at later times, following BMT in 6 recipients. Single cell cultures of CD34⁺ cells were also performed to evaluate their in vitro hematopoietic function. CD34⁺ cells were detectable in bone marrow cells on day 14. More than 80% of CD34⁺ cells co-expressed the CD33 antigen, and macrophage (Mac) colony-forming cells predominated among total colony-forming cells of CD34⁺ cells. In normal bone marrow cells, CD34⁺, CD33⁺ cells amounted to about 40% of CD34⁺ cells, and the incidences of erythroid bursts, granulocyte/macrophage (GM) colonies, and Mac colonies were similar to each other. After more than 10 weeks, CD34⁺, CD33⁻ cells gradually recovered, as erythroid burst colony-forming cells increased following GM colony-forming cells. This phenomenon was well-correlated with the time course of peripheral blood cell recovery. CD34⁺, CD33⁺ cells as committed progenitors and CD34⁺, CD33⁻ cells as multipotent stem cells have distinctive biological behaviors in BMT.     

Genetic changes and histopathological types in colorectal tumors from patients with familial adenomatous polyposis

Loss of heterozygosity (LOH) and K-ras mutation were analyzed in 111 colorectal polyps and 26 invasive carcinomas from 40 patients with familial adenomatous polyposis of distinct histopathological types. LOH, being less than 2% in moderate adenomas, was detected on chromosome 5q (20%) in severe adenomas, on 5q (26%) and 17p (38%) in intramucosal carcinomas, and on 5q (52%), 17p (56%), 18 (46%), and 22q (33%) in invasive carcinomas. LOH on chromosome 5q occurred most frequently in the region close to the APC gene both in adenomas and carcinomas, and a loss of the normal allele of the APC gene was demonstrated in 3 cases. K-ras mutation markedly increased in the step of development from moderate (11%) to severe (36%) adenomas. These results suggest the following mechanisms for the development of colon tumors in patients with familial adenomatous polyposis: (a) the heterozygous mutant/wild-type condition at the APC gene causes formation of mild or moderate adenoma; (b) the loss of the normal allele in the APC gene leads to a change from moderate to severe adenoma; (c) LOH on chromosome 17p contributes to the conversion of adenoma to intramucosal carcinoma; (d) LOH on other chromosomes, such as 18 and 22q, are involved in the progression of intramucosal carcinoma to invasive carcinoma; and (e) K-ras mutation may also affect the development of moderate to severe adenoma.     

Inspired superoxide anions attenuate blood lactate concentrations in postoperative patients

OBJECTIVE: Low concentrations of superoxide (O(2)(-)) constitute a portion of atmosphere negative ions in the form of O(2)-(H(2)O)(n), which has been reported to have a stimulatory effect on superoxide dismutase activity. If superoxide dismutase is activated by inspired negative ions containing O(2)(-), aerobic metabolism could be improved. To test this hypothesis, we examined blood lactate concentrations in postoperative patients with or without inhalation of air from a home humidifier that generates O(2)-(H(2)O)(n). DESIGN: Prospective, randomized, controlled trial. SETTING: Neurosurgical intensive care unit of a general hospital. PATIENTS: Twenty postneurosurgical patients with arterial blood lactate concentrations >1.5 mmol/L were studied and were divided randomly into two groups. INTERVENTIONS: One group received 40 L/min 40% oxygen flow from a home humidifier as an oxygen therapy for 4 hrs, followed by almost the same flow from a jet nebulizer, which generates positive ions, for 4 hrs. The other group received the reverse combination. MEASUREMENTS AND MAIN RESULTS: During the 8-hr study, arterial blood lactate concentrations were measured every hour. There was a significant difference in the time course of blood lactate concentrations between the groups. In the group in which negative ions were first initiated for 4 hrs and positive ions thereafter, the lactate concentration decreased slightly at 3, 4, and 5 hrs and returned to the baseline concentration thereafter. In the group with the reverse combination, the lactate concentration did not change during the first 4 hrs but decreased thereafter after inhalation of negative ions. CONCLUSIONS: Inspired O(2)(-) attenuates blood lactate concentrations. This may be attributed, in part, to the systemic stimulatory effect on superoxide dismutase activity, which accelerates oxidative phosphorylation in the mitochondria, thus attenuating lactate generation.