Mode of selectivity in cyclic AMP receptor protein-dependent promoters in Escherichia coli

Escherichia coli cAMP receptor protein (CRP) controls more than 20 genes. There are significant differences in the promoter regions in these genes. Thus, an elucidation of the mechanism of CRP action requires knowledge about the mode of selectivity in these promoters. An earlier study [Heyduk, T., & Lee, J. C. (1990) Proc. Natl. Acad. Sci. U.S.A. 81, 1744-8] indicates that the CRP(cAMP)1 conformer exhibits the highest affinity for the lac PI site in the lac operon. It is conceivable that the CRP conformer that binds with the highest affinity to these other sites may not be CRP(cAMP)1. To investigate this possibility, the binding of CRP to nine CRP binding sites was studied as a function of cAMP concentration. The CRP binding sites employed in this investigation were chosen to represent the primary promoter sites from class I (lac site PI) and class II (sites PI of gal and crp) as well as secondary CRP binding sites (crp site PII and cat PII) to further understand the molecular mechanism of CRP in controlling the transcription of these bacterial genes. The affinity of CRP for three synthetic CRP binding sites was also examined to explore the contribution of the inverted repeat region and sequences surrounding the recognition motifs. The synthetic sequences are gallac which contains the lac recognition motifs in the background of gal, modified cat PII which contains an 8-base pair spacer between the recognition motifs rather than the 7-base pair sequence naturally found in cat PII, and a random sequence that has no known similarity to any CRP binding site found in nature. The apparent affinities of these sequences for CRP were quantitatively determined to be biphasic in their cAMP dependence. The CRP(cAMP)1 conformer was found to have the highest affinity for all of the DNA sequences examined. No specific affinity was observed for these sequences with free CRP and CRP(cAMP)2. The affinity of CRP for DNA was sequence-dependent and increased in the following order: random < cat site PII, modified cat site PII, crp sites PI and PII < gal site PI < lac site PI < gallac. These results indicate that the entire CRP binding site sequence and its natural variability provide information to CRP. These promoter sites which appear to have different mechanisms at the molecular level are transcriptionally controlled by the same CRP conformer, CRP(cAMP)1. Thus, the regulation of transcription by CRP is more subtle than choosing different conformational forms of CRP. Using "physiological" concentrations of various components, a computer simulation study was conducted to illustrate the possible consequences of the thermodynamic parameters determined in this study. It is evident that the promoters of protein systems regulating the transport and metabolism of carbohydrates are responsive to low cAMP concentrations. However, the promoter for controlling the expression of CRP is highly regulated by the fluctuation of cAMP concentration.

CXC chemokines bind to unique sets of selectivity determinants that can function independently and are broadly distributed on multiple domains of human interleukin-8 receptor B. Determinants of high affinity binding and receptor activation are distinct

Human interleukin-8 receptors A (IL-8RA) and B (IL-8RB) are seven-transmembrane domain (TMD) neutrophil chemokine receptors with similar sequences (77% amino acid identity) and similar G protein selectivity, but markedly different selectivity for CXC chemokines. IL-8RB is selective for IL-8, growth-related oncogene alpha (GRO alpha) and neutrophil-activating peptide-2 (NAP-2), whereas IL-8RA is selective only for IL-8. To identify selectivity determinants, we made eight chimeric receptors exchanging: 1) the three main regions of sequence divergence between IL-8RA and IL-8RB (the N-terminal segment before TMD1, the region from TMD4 to the end of the second extracellular (e2) loop, and the C-terminal tail), and 2) the N-terminal segment of CC chemokine receptor 1, which does not bind CXC chemokines. Chimeras were tested by direct 125I-IL-8, 125I-GRO alpha, and 125I-NAP-2 binding, heterologous competition binding, and calcium flux assays using human embryonic kidney 293 cells stably transfected with receptor DNAs. The following results were obtained: 1) chimeric receptors had binding sites for IL-8, GRO alpha and NAP-2 distinct from those on IL-8RA and IL-8RB; 2) IL-8, GRO alpha and NAP-2 bound to overlapping but distinct sites that mapped differentially to multiple domains on IL-8RB; 3) high affinity radioligand binding and high agonist potency were separable functions for IL-8, GRO alpha and NAP-2, suggesting that the determinants of high affinity binding may not be critical for receptor activation; and 4) determinants of GRO alpha and NAP-2 selectivity were found in both the N-terminal segment before TMD1 and the region from TMD4 to the end of the e2 loop of IL-8RB, and functioned independently of each other. Stated reciprocally, the N-terminal segment of IL-8RA was not a dominant selectivity determinant. These data suggest that both narrow and broad spectrum chemokine antagonists can be developed to block functions mediated by IL-8RB.

Differential activation of ERK, JNK/SAPK and P38/CSBP/RK map kinase family members during the cellular response to arsenite

Exposure of cells to either proliferative or stressful stimuli elicits a complex response involving one or more distinct phosphorylation cascades culminating in the activation of multiple members of the mitogen-activated protein kinase (MAPK) family, including extracellular signal regulated kinase (ERK), stress-activated c-Jun N-terminal kinase (JNK/SAPK), and p38/RK/CSBP protein kinase. While the pathways transducing mitogenic stimuli to these kinases are relatively well established, the early signalling events leading to their activation in response to stress are poorly understood. In the present study, we examined ERK, JNK/SAPK, and p38 activation in cells treated with the sulfhydryl-reactive agent sodium arsenite. Arsenite treatment potently activated both JNK/SAPK and p38, but only moderately activated ERK. Activation of all three kinases was prevented by the free radical scavenger N-Acetyl-L-cysteine, suggesting that an oxidative signal initiates the responses. Suramin, a growth factor receptor poison, significantly inhibited ERK activation by arsenite, but had little effect on either JNK/SAPK or p38 activity. In contrast, suramin inhibited the activation of all three kinases by short wavelength ultraviolet light (UVC) irradiation. In addition, comparative studies with wild-type PC12 cells and PC12 cells expressing a dominant negative Ras mutant allele indicated that arsenite activates ERK primarily through a Ras-dependent pathway(s), while activation of both JNK/SAPK and p38 occurs through a mechanism relatively independent of Ras. These results suggest that JNK/SAPK and p38 may share common upstream regulators distinct from those involved in ERK activation.

Controlled cross circulation in dogs: effects on donor hemodynamics

Controlled cross circulation (CCC) was performed in six pairs of dogs for 45 minutes with aortic cross clamping and cardioplegia. Data were collected in donor dogs at 10 minute intervals three times before, three times during, and three times after CCC and included arterial blood pressure, pulmonary capillary wedge pressure (PCWP), central venous pressure (CVP), cardiac index (CI), heart rate (HR), blood gas analysis, temperature, maximum rate of rise of left ventricular pressure dP/dt max/End diastolic volume (EDV), blood volume (BV), complete blood count (CBC) and activated clotting times (ACT). Pulse pressure (PP), systemic vascular resistance (SVR), oxygen delivery (DO2), and left ventricular cardiac work (LVCW) were calculated. Arterial blood pressure, CVP, blood gas analysis, temperature, BV, CBC, and ACT were measured in recipient dogs. During CCC, donor hemodynamic changes resembled those observed in models of acute onset arteriovenous fistulas. Insidious BV shifts can occur despite the use of occlusive roller pumps. After CCC, donor hemodynamics resembled acute blood loss, characterized by decreases in mean arterial pressure (MAP), CVP, PCWP, and CI, and increases in SVR and dP/dt max/EDV. These changes were probably caused by pump imbalance and BV shift to the recipient dog.

Decrease of anesthetics activity by electroacupuncture on Jen-Chung point in rabbits

The effect of acupuncture at life-saving point on the central nervous depressive action of anesthetics was investigated in rabbits. Stimulation with electroacupuncture (EA) inserted in Jen-Chung point, which is located at the mid-point on the upper lip, decreased the sleeping time induced by pentobarbital or propofol. However, this action of acupuncture was not modified by naloxone at the doses sufficient to block opiate receptors. Plasma beta-endorphin detected by radioimmunoassay was also not markedly changed in rabbits which received similar electrostimulation. Moreover, pretreatment with para-chlorophenylalanine at a dose sufficient to deplete endogenous 5-hydroxytryptamine (5-HT) failed to influence the action of EA. Mediation of endogenous opioids and/or 5-HT in this action of EA was then ruled out. Prazosin reversed the sleeping time decreasing action of acupuncture in a dose-dependent manner. Also, the action of acupuncture was eliminated in rabbits which received intracerebroventricular injection of guanethidine at a dose which could block noradrenergic nerve terminals. It is suggested that stimulation of Jen-Chung point through EA can activate noradrenergic neurotransmission in the brain, which in turn reduces the central nervous depressive activity of anesthetics.

Multiple regions of yeast ribosomal protein L1 are important for its interaction with 5 S rRNA and assembly into ribosomes

Yeast ribosomal protein L1 binds to 5 S rRNA and can be released from 60 S ribosomal subunits as an intact ribonucleoprotein particle. To identify residues important for binding of Saccharomyces cerevisiae rpL1 to 5 S rRNA and assembly into functional ribosomes, we have isolated mutant alleles of the yeast RPL1 gene by site-directed and random mutagenesis. The rpl1 mutants were assayed for association of rpL1 with 5 S rRNA in vivo and in vitro and assembly of rpL1 into functional 60 S ribosomal subunits. Consistent with previous data implicating the importance of the carboxyl-terminal 47 amino acids of rpL1 for binding to 5 S rRNA in vitro, we find that deletion of the carboxyl-terminal 8, 25, or 44 amino acids of rpL1 confers lethality in vivo. Missense mutations elsewhere in rpL1 also affect its function, indicating that multiple regions of rpL1 are important for its association with 5 S rRNA and assembly into ribosomes.

Human mitogen-activated protein kinase CSBP1, but not CSBP2, complements a hog1 deletion in yeast

CSBP1 and CSBP2 are human homologues of the Saccharomyces cerevisiae Hog1 mitogen-activated protein kinase which is required for growth in high osmolarity media. Expression of CSBP1, but not CSBP2, complemented a hog1 delta phenotype. A CSBP2 mutant (A34V) that complements hog1 delta was isolated and found to have approximately 3-fold lower kinase activity than the wild-type CSBP2. Further analysis revealed that both the kinase activity and tyrosine phosphorylation of CSBP1 and CSBP2 (A34V) is regulated by salt. In contrast, wild-type CSBP2 is constitutively active but dependent on the upstream kinase, Pbs2. Mutagenesis studies showed that reduction or elimination of CSBP2 kinase activity restores salt responsiveness as measured by tyrosine phosphorylation suggesting that too high a level of kinase activity can result in desensitization of the host cell and inability to grow in high salt.

Further evidence that the mouse defense test battery is useful for screening anxiolytic and panicolytic drugs: effects of acute and chronic treatment with alprazolam

The Mouse Defense Test Battery (MDTB) has been designed to investigate defensive responses of Swiss-Webster mice confronted with a natural predator, a rat. These behaviors include flight, avoidance, defensive threat/attack responses, and risk assessment activities. Previous studies with the MDTB have suggested that this model may have some utility for the investigation of panicogenic and antipanic compounds. In the present study the MDTB was used to investigate the effects of acute (0.05-1 mg/kg, i.p., 30 min) or chronic (0.5-2 mg/kg, one daily i.p. injection during 10 days) treatment with the benzodiazepine receptor (BZPR) full agonist and panicolytic agent alprazolam. At non motor-impairing doses (0.05-0.5 mg/kg), acute alprazolam failed to alter the avoidance distance between the subject and the predator, the number of avoidances when the rat is approaching, predator assessment activities, defensive threat/attack responses when contact is forced between the subject and the predator or contextual escape attempts after the predator was removed. This was in contrast to chronic treatment which decreased both avoidance variables at 0.5 and 1 mg/kg, defensive threat/attack responses at all doses, and predator assessment responses at 0.5 mg/kg. In addition, the latter treatment reduced post-predator potentiation of escape attempts at 2 mg/kg. These results (1) confirm previous findings with the BZPR full agonist chlordiazepoxide, indicating that these compounds generally attenuate antipredator defensive responses in Swiss-Webster mice; (2) support recent data indicating that panic-altering drugs modulate flight/escape reactions, and suggest that the primary mechanism of action of drugs with efficacy against panic disorder may involve neural systems controlling flight; (3) confirm that the MDTB may be useful for the investigation of panicolytic as well as anxiolytic agents.

Laparoscopically assisted vaginal hysterectomy

OBJECTIVE

To report our experience with laparoscopically assisted vaginal hysterectomy (LAVH) and evaluate the advantages of LAVH.

STUDY DESIGN

From January 1991 to August 1992, 176 LAVHs were performed at the Department of Obstetrics and Gynecology, College of Medicine, Chung-Ang University, Seoul, Korea. The indications for LAVH, based on the preoperative diagnosis, were uterine myomas, dysmenorrhea, chronic pelvic inflammatory disease or pelvic pain, dysfunctional uterine bleeding and cervical intraepithelial neoplasia (in order of frequency).

RESULTS

Patients had concomitant procedures, including incidental appendectomy, posterior wall repair, pelvic adhesiolysis and salpingo-oophorectomy. Bipolar forceps were used to compress and desiccate vessels. The Nd-YAG laser, scissors and/or unipolar electrode were used for tissue division, excision of adhesions and cutting. The intraoperative complications were bladder perforation, massive hemorrhage and inferior epigastric vessel injury (one case each). The postoperative complications were infection, voiding difficulty, febrile morbidity, pelvic abscess, incisional hernia, vaginal vault bleeding and peroneal nerve palsy (one case each).

CONCLUSION

Hysterectomy can be safely performed vaginally assisted by operative laparoscopy by well-trained laparoscopists, resulting in reduced surgical morbidity, blood loss, postoperative discomfort, recovery time and hospitalization.

Inhibitors of serine/threonine kinases

Several serine/threonine kinase inhibitors have been described recently that are sufficiently selective, and therefore useful as biochemical probes, for studying the role of kinases in signaling pathways. In addition, these newer classes of kinase inhibitor may well provide an impetus for the development of drugs to attenuate certain cellular responses in the treatment of diseases. Importantly, within the past year, specific and potent inhibitiors have been reported for both the new mitogen-activated protein (MAP) kinase homolog CSBP and MAP kinase kinase-1.

Analysis of K-ras gene mutations in periampullary cancers, gallbladder cancers and cholangiocarcinomas from paraffin-embedded tissue sections

Point mutations of the K-ras gene were analyzed in 25 periampullary cancers (21 ampulla vater cancers, two common bile duct cancers and two duodenal cancers), two gallbladder cancers and six cholangiocarcinomas. DNA extracted from the paraffin-embedded tissues was amplified with the polymerase chain reaction and subsequently analyzed by direct cycle sequencing at codons 12, 13 and 18 of the K-ras gene. Codon 61 was first screened with single strand conformation polymorphism and then sequenced by direct cycle sequencing. No point mutation was found in any of the 25 periampullary cancers or the two gallbladder cancers. These results are similar to previous reports. Mutation of the K-ras gene seems not to play an important role in tumorigenesis of periampullary cancer. In two of six (33%) cholangiocarcinoma patients, point mutations were found. Both mutations were transitions, GGT to GAT at codon 12. The incidence of mutation was greater than that in Thailand (about 8%) but less than that in Japan (about 60%). Mutation of the K-ras gene may play varied roles in the tumorigenesis of cholangiocarcinoma, depending on geographic area.

c-fos and HSP70 gene expression in rat brains in high gravitation-induced cerebral ischemia

Previous studies have shown that brief exposures of rodents to high gravitational forces (+Gz) in a specifically designed centrifuge cause global cerebral ischemia. In the present study, the effect of +Gz exposure to +22.5Gz for 15 to 60 s on c-fos and HSP70 gene expression was examined. Northern and RT-PCR analyses to total RNA isolated from brains of rats in different post-exposure times revealed a significant, time-dependent increase in the c-fos mRNA level which returned to near normal by 180 min. The HSP70 mRNA level was increased two-fold at 30 min post exposure, and remained elevated until 180 min. The transient stimulation of c-fos and HSP70 gene expression should serve as useful biomarkers for hypergravic stress on the brain. The present results should aid in design of future experiments in our understanding of the pathophysiology of the high +Gz challenges.

Osteogenic protein-1 enhances phenotypic expression in ROS 17/2.8 cells

Osteogenic protein-1 (OP-1) stimulates bone morphogenesis in vivo and modulates osteoblast growth and differentiation in vitro. Treatment of ROS 17/2.8 cells with OP-1 resulted in a time- and concentration-dependent inhibition of [3H]thymidine incorporation. In contrast, OP-1 treatment stimulated phenotypic differentiation in ROS 17/2.8 cells, as indicated by enhanced 1) alkaline phosphatase activity (4-fold); 2) alkaline phosphatase mRNA (5-fold); 3) parathyroid hormone receptor mRNA (2-fold), and 4) parathyroid hormone-stimulated adenosine 3',5'-cyclic monophosphate accumulation (2-fold). OP-1-induced changes in cell growth and gene expression were sensitive to cycloheximide and actinomycin D. Measurement of [3H]thymidine incorporation and alkaline phosphatase activity in situ revealed heterogeneity in the cellular responses to OP-1. Proliferating cells exhibited less alkaline phosphatase activity than nonproliferating cells, whereas cells expressing high levels of alkaline phosphatase incorporated little [3H]thymidine. Our data delineating the responses of mature differentiated osteoblasts to OP-1 suggest that potentiation of osteoblast differentiated function is an important component of bone morphogenesis in vivo.

Genotyping of the DQA1*4 alleles by restriction enzyme digestion of the PCR product from the AmpliType PM kit

An earlier study has shown that the three DQA1*4 alleles (0401, 0501 and 0601) can be distinguished by restriction enzyme digestion of the polymerase chain reaction (PCR) product derived from the DQ alpha AmpliType kit (Perikin-Elmer, Norwalk, NJ). We have found that the AmpliType PM kit (Perkin-Elmer, Branchburg, NJ) can also be used to achieve the same goal. In this case, a Bio-Profil image analysis system (Vilber Lourmat, Marne La Vallee, France) is used for evaluating the restricted patterns. After typing the six alleles of DQA1 by the AmpliType HLA DQ alpha Detection Reagent Set (Perkin-Elmer, Branchburg, NJ), the PCR products from the PM kit with allele 4 were digested with Fok I and RsaI, separately. Since the other five fragments from PM kit will conceal the digested fragments of the HLA DQA1 PCR products, we measured the optical density of the pre- and post-digested 242 bp fragments in Fok I digestion, and 214/221 bp fragments in Rsa I digestion to decide the results of enzyme digestion. Out of 136 samples used in this study, 61 contain the DQA1 allele 4 determined by the DQ alpha AmpliType method. All 61 were typed with enzyme digestion, of which there are 2.3%, 19.8% and 8.1% in allele 0401, 0501 and 0601, respectively. Our procedure can thus extend the utilization of AmpliType PM kit and increase the discrimination power of the DQA1 system, especially in populations with high distribution of allele 4.

A CD10-positive subset of malignant cells is identified in multiple myeloma using PCR with patient-specific immunoglobulin gene primers

Immunophenotypic studies show the presence of CD10-bearing malignant cells in a small subset of multiple myeloma (MM) patients. We used a sensitive PCR-based technique in order to determine the frequency that MM patients contain a malignant subpopulation which expresses this antigen. The immunoglobulin (Ig) heavy chain variable region (VH) gene sequence expressed by the malignant clone in MM can be used as a tumor specific marker. After determining this sequence in six MM patients, patient specific VH oligonucleotide primers from complementarity determining region (CDR) sequences were generated. Bone marrow mononuclear cells from these patients were incubated with two different anti-CD10 antibodies or isotype identical murine IgG controls. Cells were then sorted by flow cytometry into the 1% brightest cells containing > 99.99% CD10-positive cells and two fractions including the 90 and 10% dimmest staining cells. PCR amplification was performed on DNA from approximately 10(4) cells (0.1 microgram) using patient specific CDR1 and CDR3 primers. Detectable PCR product was obtained in each sorted sample although the intensity of the band was much higher in cells lacking CD10 expression (the 90 and 10% dimmest fractions) than in the CD10-bearing (1% brightest) population. These results imply that there is a small population of CD10-bearing clonal cells in most, if not all patients with MM.

The relationship between an endangered North American tree and an endophytic fungus

BACKGROUND

The Florida torreya (Torreya taxifolia) began a catastrophic decline in the late 1950s and is now the rarest tree in North America for which a full species designation has been established. The trees have common plant disease symptoms, but the reason for the decline has never been identified. T. taxifolia's imminent extinction gains special poignancy through its close relationship to the Pacific yew (Taxus brevifolia), which produces the potent anticancer agent, taxol.

RESULTS

An examination of the endophytic fungal communities of wild torreyas consistently found a filamentous fungus, Pestalotiopsis microspora, associated with diseased trees and also with most symptomless trees. P. microspora can be cultured in the laboratory, and when it is introduced into greenhouse-grown torreyas, it causes disease symptoms similar to those seen in the field. The fungus can then be reisolated from these deliberately infected trees. The phytotoxins pestalopyrone, hydroxypestalopyrone and pestaloside have been isolated and characterized from axenic fungal cultures, and both pestalopyrone and hydroxypestalopyrone can be isolated from artificially infected torreyas. In addition, pestaloside has antifungal activity against other fungal endophytes of T. taxifolia.

CONCLUSIONS

The filamentous fungus, P. microspora, has an endophytic-pathologic relationship with T. taxifolia. The fungus resides in the inner bark of symptomless trees, and physiological or environmental factors could trigger its pathological activity. P. microspora produces the phytotoxins pestalopyrone, hydroxypestalopyrone, and pestaloside which give rise to the disease. Pestaloside, which also has antifungal activity, could reduce competition from other fungal endophytes within the host.

Identification of a Drosophila muscle development gene with structural homology to mammalian early growth response transcription factors

In Drosophila, stripe (sr) gene function is required for normal muscle development. Some mutations disrupt embryonic muscle development and are lethal. Other mutations cause total loss of only a single muscle in the adult. Molecular analysis shows that sr encodes a predicted protein containing a zinc finger motif. This motif is homologous to the DNA binding domains encoded by members of the early growth response (egr) gene family. In mammals, expression of egr genes is induced by intercellular signals, and there is evidence for their role in many developmental events. The identification of sr as an egr gene and its pattern of expression suggest that it functions in muscle development via intercellular communication.

Application of ABO genotyping using polymerase chain reaction method to assess engraftment in bone marrow transplantation--a case report

We described a case of acute promyelocytic leukemia with O blood type who received bone marrow transplantation during a second remission from his HLA identical, B blood type sibling. Using PCR genotyping of the ABO group and analysis of the variable number of tandem repeats of the D1S80 locus, we could quickly document the successful early engraftment in this patient. We emphasize that the use of PCR ABO genotyping is a quick and valuable method which could be applied to assess the engraftment and its follow up in those transplant cases with donors of mismatched blood groups.

Myeloma Ig heavy chain V region sequences reveal prior antigenic selection and marked somatic mutation but no intraclonal diversity

The lg VH region sequence in 48 patients with multiple myeloma (MM) was analyzed to characterize the malignant cell of origin. The sequences were obtained after amplification of bone marrow cDNA by using VH family-specific and CH primers, then compared with either directly sequenced patient germ-line or published VH gen sequences to assay for somatic mutation. Because somatic hypermutation of the VH gene occurs late in B cell development, its presence has been helpful in determining the cell of origin in other B cell malignancies. Overall, a median of 8.2% of the nucleotides had evidence of substitution within each VH gene sequence (range=2.7% to 16.5%), which is more prevalent than in any other reported tumor type. Strong evidence of prior antigenic selection pressure was also evident. The ratio of nucleotide substitutions that resulted in amino acid replacement was significantly higher in the complementarity-determining region than in the framework region (3.25 vs 1.56, respectively; p < 0.00005). No VH gene intraclonal diversity was noted, despite sequencing multiple clones (3-16) from each patient, nor was there evidence of further VH gene somatic mutation over the course of three patients' disease. These findings strongly imply that the malignant clone in MM evolves from a cell late in B cell development.

Myeloma Ig heavy chain V region sequences reveal prior antigenic selection and marked somatic mutation but no intraclonal diversity

The lg VH region sequence in 48 patients with multiple myeloma (MM) was analyzed to characterize the malignant cell of origin. The sequences were obtained after amplification of bone marrow cDNA by using VH family-specific and CH primers, then compared with either directly sequenced patient germ-line or published VH gen sequences to assay for somatic mutation. Because somatic hypermutation of the VH gene occurs late in B cell development, its presence has been helpful in determining the cell of origin in other B cell malignancies. Overall, a median of 8.2% of the nucleotides had evidence of substitution within each VH gene sequence (range=2.7% to 16.5%), which is more prevalent than in any other reported tumor type. Strong evidence of prior antigenic selection pressure was also evident. The ratio of nucleotide substitutions that resulted in amino acid replacement was significantly higher in the complementarity-determining region than in the framework region (3.25 vs 1.56, respectively; p &lt; 0.00005). No VH gene intraclonal diversity was noted, despite sequencing multiple clones (3-16) from each patient, nor was there evidence of further VH gene somatic mutation over the course of three patients' disease. These findings strongly imply that the malignant clone in MM evolves from a cell late in B cell development.

Adenoma-carcinoma sequence: a reappraisal with immunohistochemical expression of ferritin

To examine the biological significance of ferritin (FRN) expression, a retrospective immunohistochemical study was performed in normal colonic mucosae (n = 8), adenomas (n = 88), and colorectal carcinomas (n = 104). FRN was present in some epithelia in the crypt base of normal colonic mucosae. Significant cytoplasmic staining for FRN was revealed in 26 (29.5%) cases of adenoma and 54 cases (51.9%) of adenocarcinoma. The cancer cells had a higher proportion of FRN expression than those of adenomas or non-neoplastic mucosae (P < 0.001). Expression of FRN showed a positive association with the degree of dysplasia (P = 0.039) and the distal location of adenoma (P = 0.013). FRN expression tended to be associated with the tumor size (P = 0.083), but no substantial difference was observed among the histologic types of adenoma (P = 0.754). The results suggest that cytoplasmic FRN expression is associated with cellular proliferation. The proliferative index shows a significant difference through the adenoma-carcinoma sequence. Further investigation is necessary to clarify the clinical implication of FRN expression in tumor cells and normal-appearing mucosae.