Absence of microsatellite instability during the progression of chronic myelocytic leukemia.

Microsatellites are highly polymorphic, short-tandem repeat sequences dispersed throughout the genome. To test the occurrence of genetic instability in the progression of chronic myelocytic leukemia (CML), we studied microsatellite instability (MSI) in 17 patients with CML. The DNAs from both chronic phase and blast crisis were analyzed at 10 loci. No MSI was observed in any of the 17 cases of blast crisis. These results indicate that MSI is rare and is not associated with progression to blast crisis in most cases of CML.

Allelotyping of acute myelogenous leukemia: loss of heterozygosity at 7q31.1 (D7S486) and q33-34 (D7S498, D7S505).

Loss of a whole chromosome 7(-7) or a deletion of the long arm of chromosome 7 del(7q) occurs frequently in many types of primary cancers including cases of acute myelogenous leukemia (AML). We analyzed for loss of heterozygosity (LOH) of chromosome arm 7q in 26 AML cases using a set of 15 microsatellite markers in order to begin to determine the location of putative tumor suppressor genes (TSG) important to this disease. Seven samples (27%) showed LOH at one or more loci on chromosome 7q. We identified the smallest commonly deleted regions to be at 7q31.1 (D7S486) and 7q33-34 (D7S498, D7S505) suggesting that alterations of a TSG in each region have an important role in de novo AML.

Infrequent microsatellite instability during the evolution of myelodysplastic syndrome to acute myelocytic leukemia.

Microsatellites are highly polymorphic, short-tandem repeat sequences dispersed throughout the genome. Instability of these repeat sequences at multiple gentic loci may result from mismatch repair errors and occur in hereditary nonpolyposis colorectal cancer and several other sporadic cancers, including chronic myelocytic leukemia as it progresses to blastic crisis. We investigated whether genetic instability occurred as myelodysplasia progressed to acute myelocytic leukemia. To this end, we studied microsatellite instability in 20 patients with myelodysplastic syndrome (MDS). These included five patients with refractory anemia (RA), three with refractory anemia with ringed sideroblast (RARS), nine with refractory anemia with excess blasts (RAEB) and three with chronic myelomonocytic leukemia (CMML). All of these patients transformed to acute myelocytic leukemia (AML) of various subtypes: three patients with M1, 11 with M2 and six patients with M4 (according to FAB classification). The DNA from both the MDS and AML phases of their disease was analyzed at 16 loci, and only four microsatellite instabilities were found in the 240 paired samples (1.6%) analyzed. These results indicate that mismatch repair errors such as microsatellite instability are not important in the evolution of MDS to AML.

DNA aneuploidy in morphologically normal colons from patients with colon cancer.

DNA aneuploidy is common in colon carcinoma, colonic polyps, and ulcerative colitis. We found an interesting subset of patients with colon cancer. These individuals (14 of 230 cases, 6%) had hypodiploid aneuploidy in their morphologically normal-appearing colonic tissue. The aneuploid fractions were small, making up between 10 to 15% of the total events, and the ploidy pattern was not related to the ploidy pattern of the tumor. The clinical findings of the 14 patients were compared with those of patients who had diploid normal colons by age, location of the tumor, Dukes stage, and percent aneuploidy in the main tumor; the two groups were comparable. Both the normal colon and carcinomas of the 14 cases were studied by a newly developed "enriched" polymerase chain reaction for K-ras mutations. No K-ras mutations were found in the normal tissues, but mutations were found in the tumors of four cases. Cells from some colon cancers have a high degree of genetic instability, as shown by numerous mutations throughout the genome. Analysis of eight matched colon cancers and aneuploid, morphologically normal-appearing colons for genetic alterations, as measured by shifts in the electrophoretic mobility of microsatellite repeat fragments, showed that only one of eight colon cancer samples had microsatellite instability, which is the expected frequency. Taken together, the data suggest that individuals with colon cancer may have morphologically normal colonic tissue, which is genetically abnormal, and this abnormality may precede the development of mutations in K-ras.(ABSTRACT TRUNCATED AT 250 WORDS)

Microsatellite instability during the progression of acute myelocytic leukaemia.

We studied microsatellite instability (MSI) at the onset and during progression of 17 individuals with acute myelocytic leukaemia (AML). These included two cases of MO, eight with M1 and seven with M4, according to the FAB classification. The DNA from diagnostic, remission and relapsed stages of their disease was analysed at 69 loci. Two MSI were found in the diagnostic and remission phase paired samples (12%), and eight MSI were identified in six of the relapsed phase samples (35%). These results indicate that mismatch repair errors such as MSI are unimportant at the onset of AML, but might have importance during the progression of the disease.

Preadmission screening of patients scheduled for hip and knee replacement: impact on length of stay.

OBJECTIVE: An evaluation of the impact of a social work preadmission program on length of stay (LOS) of orthopedic patients undergoing elective total hip or total knee replacement surgeries (under diagnosis-related groups [DRGs]) at the Hadassah Ein-Kerem Hospital in Jerusalem is Israel. INTERVENTION: The social work interventions included preadmission psychosocial evaluation and preliminary discharge planning, coordination of nursing and physiotherapy evaluations, ensuring completion of all medical tests prior to admission, and additional psychosocial follow-up during hospitalization to carry out the original discharge plan or prepare alternatives. PATIENTS: The intervention patients were divided into two groups in order to see changes over time: May through December 1994 (n = 48), and January through December 1995 (n = 81). The comparison groups included patients operated on at the same hospital during 1993 (n = 51) and during January through April 1994 (n = 21) and at the Hadassah Mount Scopus Hospital during the same time periods. Patients in the comparison groups received usual social work intervention, as necessary, only after hospitalization. RESULTS: Mean LOS was reduced significantly in the intervention patient groups, as compared to the preintervention patient groups in the same hospital, from 14.2 days (standard deviation [SD], 4.7) in 1993 and 14.7 (SD, 5.1) in January through April 1994 to 10.9 (SD, 3.0) in May through December 1994 and to 9.1 (SD, 2.8) in 1995 (P < .01). Length of stay also was reduced in the comparison hospital, but by 1995 was longer than in the intervention patients. No differences in LOS by gender, age, or marital status were found. Length of stay was significantly longer for those undergoing total hip replacement as compared to those undergoing total knee replacement in all the groups. CONCLUSIONS: Preadmission screening and case management by a social worker can contribute to the efforts to decrease LOS of orthopedic patients by early multidisciplinary evaluations, discharge planning, and coordination of services.

Allelotype analysis in the evolution of chronic myelocytic leukemia.

To elucidate the genetic events that may play important roles in the progression of chronic myelocytic leukemia (CML), we performed allelotype analysis in 30 patients with CML as the disease transformed to accelerated phase or blast crisis (21 myeloid and 9 lymphoid cases). DNAs were extracted from slides of bone marrow smears or from freshly isolated bone marrow mononuclear cells. The DNAs from the same individuals in both chronic phase and either blast crisis or accelerated phase were analyzed at 82 microsatellite markers, which mapped to each of the autosomal arms except the short arms of the acrocentric chromosomes. Loss of heterozygosity (LOH) on at least one locus was observed in 21 of the 30 cases (70%) as the disease progressed. Frequent allelic loss of > or = 20% of the informative cases was observed on chromosome arms 1p (35%), 7p (21%), 19p (20%), and 20q (29%). Allelic losses were also analyzed according to phenotypes. LOH of > or = 20% was detected on 1p (29%), 18p (20%), and 20q (27%) in myeloid blast crisis, and on 1p (50%), 4p (25%), 7p (43%), 9p (29%), 18q (25%), 19p (43%), and 20q (33%) in lymphoid blast crisis. Serial cytogenetic information was available for most of our cases with LOH on these arms, and only one case had loss of both chromosomes 9 and 20. Fractional allelic loss, calculated for each sample as the total number of chromosomal arms lost/total number of arms with information, showed a median value of 0.06 and a mean of 0.098 (range 0 to 0.60). These results suggest that tumor suppressor genes especially on 1p, 7p, 19p, and 20q probably have an important role in the progression to blast crisis of CML.

Chromosome band 1p36 contains a putative tumor suppressor gene important in the evolution of chronic myelocytic leukemia.

Chronic myelocytic leukemia (CML) is a common neoplasm of hematopoietic pluripotent stem cells. Although the evolution from chronic phase to blast crisis (BC) in CML patients is an inevitable clinical feature, little is understood about the mechanisms responsible for the transformation. We have previously performed allelotype analysis in CML BC and have detected frequent loss of heterozygosity (LOH) on the short arm of chromosome 1. To know the common region of LOH where a putative tumor suppressor gene may reside, deletional mapping was performed using 33 microsatellite markers spanning chromosome 1 in 30 patients with CML BC (21 myeloid and 9 lymphoid). DNA was extracted from slides of bone marrow smears or from bone marrow mononuclear cells. In each patient, DNA from chronic phase was analyzed alongside DNA from either their BC or accelerated phase. Allelic loss on 1p was observed in 14 of the 30 individuals (47%): 10 of the 21 myeloid and 4 of the 9 lymphoid BC cases. Serial cytogenetic information was available in 10 cases with LOH on 1p; interestingly, deletions in this region were not detected. Two samples showed LOH at all informative loci on 1p, whereas the other 12 samples showed LOH on at least one but not all loci on 1p. The common region of LOH resided proximal to D1S508 and distal to D1S507 (1p36). Our results suggest that a tumor suppressor gene that frequently plays an important role in the evolution to BC resides on 1p36 in CML.

Cyclin A1 expression in leukemia and normal hematopoietic cells.

Human cyclin A1 is a newly cloned, tissue-specific cyclin that is prominently expressed in normal testis. In this study, we showed that cyclin A1 was highly expressed in a subset of leukemia samples from patients. The highest frequency of cyclin A1 overexpression was observed in acute myelocytic leukemias, especially those that were at the promyelocyte (M3) and myeloblast (M2) stages of development. Cyclin A1 expression was also detected in normal CD34(+) progenitor cells. The expression of cyclin A1 increased when these cells were stimulated to undergo myeloid differentiation in vitro. Taken together, our observations suggest that cyclin A1 may have a role in hematopoiesis. High levels of cyclin A1 expression are especially associated with certain leukemias blocked at the myeloblast and promyelocyte stages of differentiation.