High-dose-rate intracavitary irradiation using linear source arrangement for stage II and III squamous cell carcinoma of the uterine cervix

PURPOSE

The purpose of this article is to evaluate fractionated high-dose-rate (HDR) intracavitary irradiation using linear source arrangement (LSA) for patients with squamous cell carcinoma of the uterine cervix.

MATERIALS AND METHODS

The subjects consisted of 217 patients (71 patients with stage II and 146 with stage III disease) who received external beam therapy (EBT) followed by fractionated HDR intracavitary irradiation using LSA between January 1980 and June 1990. In EBT, 40 Gy in 20 fractions (40 Gy/20 Fr) or 39.6 Gy/22 Fr was delivered to the whole pelvis and an additional 10 Gy/5 Fr or 10.8 Gy/6 Fr was delivered to the parametrium. The intracavitary irradiation dose was 30 Gy/6 Fr or 35 Gy/7 Fr with a daily fraction size of 5 Gy and two fractions per week. During the intracavitary treatment, most patients were treated on an out-patient basis.

RESULTS

Cause-specific 5-year survival rates were 77% for stage II and 50% for stage III. Pelvic failure rates were 13% for stage II and 36% for stage III. In multivariate analyses, improved cause-specific survival was significantly associated with stage II (P = 0.0003), higher pretreatment serum hemoglobin level (P = 0.0015), higher pretreatment serum total protein level (P = 0.0029), and shorter total treatment time (P = 0.0024). The rate of severe (grade 3 or 4) late complication was 2% for the rectum, 1% for the small intestine or sigmoid colon and 1% for the bladder.

CONCLUSIONS

Fractionated HDR intracavitary irradiation using LSA is an effective treatment for patients with uterine cervical cancer without need for hospitalization.

Effects of progestins on the metabolism of cancellous bone in aged oophorectomized rats

The effects of progestins on bone loss in female oophorectomized (ovx) rats were evaluated. One-year-old Sprague-Dawley rats were divided into eight groups: (1) beginning controls (control); (2) sham-operated controls (sham); (3) ovx; (4) ovx treated with estrogen (ovx + E); (5) ovx treated with progesterone (ovx + P); (6) ovx treated with estrogen and progesterone (ovx + E + P); (7) sham group treated with estrogen (sham + E); and (8) sham group treated with progesterone (sham + P). Immediately after surgery, the rats in the hormone injected groups were subcutaneously (s.c.) injected daily for 15 weeks with estrogen (17-beta-estradiol, 0.01 mg/kg in ethanol), or progesterone (4-pregnene-3,20-dione, 0.1 mg/kg in ethanol), or both. At the end of 15 weeks, the bone mineral density (BMD) and bone histomorphometry of the rats' lumbar vertebrae and serological parameters were measured. In the sham, ovx, and ovx + P groups, treatment with progesterone alone did not maintain the BMD in the lumbar vertebrae, but in the ovx + E and ovx + E + P, sham + E, and sham + P groups, progesterone did not inhibit the action of estrogen in the aged ovx rat model. BMD in the sham + P group was significantly higher than in the sham group (270.8+/-10.8 mg/cm2 versus 253.6+/-10.2 mg/cm2; p < 0.01). Bone histomorphometry revealed that bone volume (BV/TV) increased more in the ovx + E + P group than in the ovx + E group and more in the sham + P group than in the sham group, but not significantly. The ovx + E, ovx + E + P, sham + E, and sham + P groups showed no significant differences in the bone formation and resorption parameters, but the bone formation variables tended to increase in the ovx + E + P and sham + P groups. We concluded that progesterone alone cannot prevent bone loss or the increase in turnover after ovx and that estrogen, not progesterone, accounted for all of the bone activity in this study. It seems doubtful that progesterone inhibits the action of estrogen, and in fact may have a beneficial effect on bone metabolism.

Bactericidal domain of lactoferrin: detection, quantitation, and characterization of lactoferricin in serum by SELDI affinity mass spectrometry

Lactoferricin is a bioactive peptide fragment (3196 Da) derived from lactoferrin (80 kDa) that contains the bactericidal domain and the lymphocyte receptor-binding domain of lactoferrin. Although lactoferricin has been produced from lactoferrin by proteolytic digestion in vitro, its natural occurrence and distribution in vivo are still not clear, in part because of the absence of a suitable detection means. Surface-enhanced laser desorption/ionization (SELDI) was used to detect and characterize lactoferricin by affinity mass spectrometry. Human, porcine, and bovine lactoferricin in unfractionated serum samples were found to bind specifically to ligands presenting a terminal n-butyl group. SELDI was used to detect and quantify each species of lactoferricin in a manner that was independent of the presence of intact lactoferrin, partially degraded lactoferrin, and lactoferrin peptides containing the lactoferricin peptide sequence. The limit of detection of bovine lactofericin in serum was as low as 200 pg/ml. The FKCRRWQWR-homoserine/-homoserine lactone moiety of bovine lactoferricin, which includes the complete antimicrobial center (i.e., RRWQWR), was shown to be responsible for interaction with the n-butyl group. The SELDI procedure defined here is the only molecular recognition tool known to date that is capable of distinguishing the multi-functional lactoferricin domain located within structurally related but distinct forms of lactoferrin and its metabolic fragments. Enabling the direct quantitation of lactoferricin produced in vivo opens new opportunities to evaluate lactoferrin function.

Distribution of glycoproteins with beta-N-acetylgalactosaminylated N-linked sugar chains among bovine tissues

Only a small number of glycoproteins has been reported to contain N-linked sugar chains with GalNAcbeta1-->4GlcNAc structure. Our previous studies showed that most glycoproteins from bovine milk fat globule membranes contain beta-N-acetylgalactosaminylated N-linked sugar chains [Sato et al., J. Biochem. 114 (1993) 890-900]. In order to study how widely this glycosylation occurs, lectin blot analysis of membrane glycoproteins from 12 bovine tissues was performed using Wistaria floribunda agglutinin (WFA), which interacts with oligosaccharides terminating with N-acetylgalactosamine. The WFA-positive bands were detected in samples from most tissues except for intestine although the number and reactivity of bands to lectin varied among the tissues. Upon pretreatment of blotted filters with Bacillus beta-N-acetylgalactosaminidase or N-glycanase, no lectin binding was observed. WFA-agarose column chromatography of oligosaccharides released by hydrazinolysis from membrane glycoproteins of bovine tissues except for intestine revealed that a few to 18% of the released oligosaccharides bind and are eluted from the column with 100 mM N-acetylgalactosamine. These results indicate that many glycoproteins from a variety of bovine tissues contain N-linked sugar chains with GalNAcbeta1-->4GlcNAc structure, suggesting a wider occurrence of this glycosylation in bovine tissues.

Characterization of aminopeptidase N from the brush border membrane of the larvae midgut of silkworm, Bombyx mori as a zinc enzyme

Three GPI-anchored proteins, aminopeptidase N, alkaline phosphatase and alkaline phosphodiesterase I were released from the midgut brush border membrane of Bombyx mori by phosphatidylinositol-specific phopholipase C and the aminopeptidase N was purified to a homogeneous state. N-terminus and 6 internal sequences, one of which possessed part of zinc-binding motif, showed homology with those from other species. The zinc content in purified aminopeptidase N was estimated as approximately 0.72 mol/mol of the protein and 1,10-phenanthroline completely inhibited the enzyme activity, suggesting zinc requirement for the activity. The aminopeptidase N activity was inhibited not only by probestin and actinonin, but also strongly depressed by amastatin, while leuhistin and bestatin were less inhibitory. These suggest that the active site of aminopeptidase N might be structurally different from those of mammals. Calcium and magnesium ions stimulated the aminopeptidase N activity, but copper ion was rather inhibitory. Zinc ion showed bi-modal effect on the activity, i.e., stimulatory at low concentration, but inhibitory at higher than 100 microM. This inhibition was completely restored by EDTA. These results suggest that the aminopeptidase N possesses two zinc ion-binding sites with high and low affinity as essential and inhibitory one, as well as some regulatory metal-binding sites.

Distribution and synthesis of apolipoprotein J in the atherosclerotic aorta

The distribution of apolipoprotein (apo) J during the development of atherosclerosis in the human aorta was evaluated by immununohistochemical observation, together with the other apolipoprotein A-I, A-II, B, C-III, and E. Although apoJ was never observed in the normal aorta (ie, without any intimal lesions or intimal thickening), it was distributed not only in the intima but also in the media of aortas with diffuse, intimal thickening or atherosclerotic lesions. Double immunostaining with antibodies for apoJ and alpha-smooth muscle actin revealed apoJ deposition in smooth muscle cells (SMCs) or the aortic stroma in the vicinity of SMCs. The extent of apoJ distribution in the aortic wall increased with the degree of atherosclerosis development. In addition, the distribution pattern of apoJ was very similar to that of apoA-I and E. In situ hybridization with human apoJ cDNA demonstrated intense signals in cells scattered within the subendothelial space and medial SMCs of the aorta with advanced atherosclerosis but not in those of the normal aorta without intimal thickening. Furthermore, reverse transcriptase-polymerase chain reaction of the cultured human aortic SMCs revealed apoJ mRNA expression in these cells. The results indicate that apoJ in the aortic wall originates from not only apoJ circulated in the plasma but also apoJ produced by SMCs in the aortic wall. Considering the similarities of the distribution between apoJ and apo-A-I or E, we hypothesize that apoJ possibly has a protective role against human atherosclerosis by its involvement with cholesterol transport from the aortic wall to the liver.

Absorption-enhancing effects of sodium caprate and palmitoyl carnitine in rat and human colons

We examined the enhancing action of sodium caprate and palmitoylcarnitine on the permeability of fluorescein isothiocyanate dextran 4000 as a paracellular permeant compound in isolated rat and human colon samples using the Ussing-type chamber method. In the absence of an enhancer, the permeation clearance of fluorescein isothiocyanate dextran 4000 was not significantly different in the rat and human colons, but the electric membrane resistance was smaller in the rat colon than in the human colon. Sodium caprate and palmitoylcarnitine increased permeation clearance and decreased electric membrane resistance in both types of colonic membrane, showing that the rat colon can be used as a model of the human colon for studies of enhancer effects. A calmodulin antagonist significantly inhibited the action of sodium caprate in both colonic membranes. However, it tended to promote the effects of palmitoylcarnitine on permeation clearance and electric membrane resistance. These results suggest that sodium caprate induces the contraction of the perijunctional actomyosin ring to widen the tight junction and that the mechanism of palmitoylcarnitine is different from that of sodium caprate in the human colon, as reported previously for Caco-2 cell monolayers.

Malignant peripheral nerve sheath tumors developing multifocally in the central nervous system in a patient with neurofibromatosis type 2

We describe autopsy findings of multifocal malignant peripheral nerve sheath tumors (MPNSTs) appearing in the central nervous system in a 45-year-old Japanese female with neurofibromatosis type 2. Multiple MPNSTs were detected in both III and VIII, left IV, and V cranial nerves, and a number of nerve roots of the spinal cord. Neurofibromata were on the other hand evident on some nerve roots of the spinal cord and femoral and sciatic nerves. Our results suggest that a mutation of p53 gene may have played a role in the malignant transformation of nerve tumors in this patient since p53 protein was immunohistochemically detected in MPNST cells but not in tumor cells of the neurofibromata.

Effect of long-term hormone replacement therapy on the bone in ovariectomized women with cancer

OBJECTIVE

To evaluate longitudinally the effectiveness of long-term hormone replacement therapy (HRT) in preserving the bone mineral density (BMD) over a 5-year period in ovariectomized patients treated for gynecologic malignancies.

METHODS

A total of 70 pre-menopausal women ovariectomized for gynecologic malignancies at our hospital were divided non-randomly into two groups: HRT (+) group (n = 59) and HRT (-) group (n = 11). HRT was administered in a sequential regimen of 0.625-1.25 mg conjugated estrogen for 24 days and 5-10 mg medroxyprogesterone acetate for 10 days.

RESULTS

The BMD of the lumbar vertebrae decreased significantly in the HRT (-) group (pre-operative BMD was 91.8%, 91.0% and 91.3% at 1, 2 and 3 years post-ovariectomy), but no decrease in the BMD was observed in the HRT (+) group (pre-operative BMD was 98.4%, 99.0%, 99.4%, 98.8% and 98.7% at 1, 2, 3, 4 and 5 years post-ovariectomy); the difference in BMD between the two groups was statistically significant (P < 0.01). Serum alkaline phosphatase levels were significantly lower in the HRT (+) group than in the HRT (-) group (P < 0.01). There were four recurrences of cancer in the HRT (+) group.

CONCLUSION

HRT appeared to have beneficial effects on bone metabolism by maintaining BMD for 5 years in ovariectomized patients for gynecologic malignancies.

[Study on the relationship between tumour necrosis factor gene polymorphism and prognosis in the patients with renal cell carcinoma]

BACKGROUND

Clinical significance of polymorphism of tumour necrosis factor (TNF) genes encoded on the short arm of the 6th chromosome in the patients with renal cell carcinoma (RCC) has not been evaluated well so far. We studied on the TNF genes polymorphism of RCC focusing on the relationship between the genetic polymorphism and the prognosis.

METHODS

The subjects were seventy-three patients with RCC treated at our hospitals during the past 20 years. The genomic DNA was examined by the methods of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) from frozen peripheral blood of these patients. The items examined were the genetic polymorphisms of TNF-alpha (alpha 1, alpha 2) and TNF-beta (beta 1, beta 2), and we tried to study on the prognostic outcome of RCC based upon each zygote of TNF.

RESULTS

1) The proportion of TNF-alpha and TNF-beta polymorphisms: We observed TNF-alpha 1/1 homozygote in 71 patients (97.3%). As to TNF-beta polymorphism, we observed TNF-beta 2/2 homozygote in 33 patients (45.2%), TNF-beta 1/2 heterozygote in 31 (42.5%) and TNF-beta 1/1 homozygote in 9 (12.3%). The proportion of TNF-beta polymorphism was almost the same as that of healthy Japanese. 2) PROGNOSIS: Regarding the 17-year survival, all patients with TNF-beta 1/1 homozygote were alive, and we observed a significantly favourable prognosis in the patients with TNF-beta 1/1 homozygote compared with other zygotes of TNF-beta polymorphism. The reasons for these favourable prognosis were thought that the patients with TNF-beta 1/1 homozygote showed much lower stage and/or grade than those of other zygotes.

CONCLUSION

We conclude that the TNF-beta gene polymorphism is a useful marker for understanding the prognosis of RCC and a part of cellular immunity related to the tumour and its host.

Glutamate-stimulated proliferation of rat retinal pigment epithelial cells

We investigated the effects of glutamate on cell proliferation and the expression of basic fibroblast growth factor (bFGF) and its receptor (FGF-R1) mRNA in cultured rat retinal pigment epithelial (RPE) cells. The number of primary RPE cells was significantly higher after treatment with 0.2 to 1.0 mM glutamate (maximum at 1.0 mM) for 7 days than in controls. Glutamate-stimulated cell proliferation was abolished by (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine (MK-801), but not by 6,7-dinitroquinoxaline-2,3-dione or L(+)-2-amino-3-phosphonopropionic acid. Proliferation was increased to a similar extent by N-methyl-D-aspartate (NMDA), but not by kainate, alpha-amino-3-hydroxy-3-methyl-4-isoxazolepropionic acid or trans-(+/-)-1-amino-1,3-cyclopentanedicarboxylic acid. NMDA-receptor-like immunoreactivity was detected in most cells cultured. Treatment of cells with glutamate increased the level of bFGF mRNA and, to a lesser extent, that of FGF-R1 mRNA, which peaked 2 and 4 days, respectively, after glutamate was added. The increase in bFGF mRNA induced by glutamate was inhibited by MK-801. These findings suggest that glutamate might stimulate proliferation of RPE cells through activation of NMDA receptors and expression of bFGF and further suggest that glutamate may be involved in the proliferative changes of RPE cells in retinal wound healing.

Arylsulfatase exists as non-enzymatic cell surface protein in sea urchin embryos

The physiological role of arylsulfatase (Ars) and its function during development have yet to be satisfactorily defined in any species, though the proteins are widely distributed and the genes have been cloned from various organisms. Here we report the dual location of two types of Ars in sea urchin embryos. The majority of sea urchin Ars does not exhibit enzyme activity and is extracellularly distributed in aboral ectoderm cells (nonenzymatic Ars). Only a small portion has enzyme activity and is localized in lysosomal vesicles (enzymatic Ars). The elution pattern of Ars proteins processed by DEAE-cellulose or analytical gel-column chromatography reveals that although the molecular radius of enzymatic Ars differs from that of nonenzymatic Ars, they have the same charge. Furthermore, sedimentation analysis shows that purified Ars of sea urchin embryos is soluble in the absence of divalent cations but becomes insoluble in the presence of Ca2+ or Mg2+. Taken together, the present results suggest that non-enzymatic Ars is a new member of the cell surface component or extracellular matrix. It is possible that this cell surface Ars plays an important role in morphogenesis of sea urchin embryos.

Piglets produced by transfer of vitrified porcine embryos after stepwise dilution of cryoprotectants

A total of 498 porcine embryos at various stages of development collected from superovulated gilts was used to investigate cryopreservation. First, blastocysts (BL), expanded blastocysts (ExB), and hatched blastocysts (HB) were used to determine the effect of exposure to concentrated solutions of ethylene glycol as cryoprotective additives (CPAs) on embryo survival. Then, survival of other embryos after vitrification by rapid cooling was determined. Based on their development after 48 h in culture, embryos were not injured by being exposed to 2.0 M ethylene glycol (EG) for 15 min or to 2.0 M EG for 5 min and then to a solution of 8.0 M EG in 7% polyvinylpyrrolidone (PVP) for 1 min. The CPAs were removed from the embryos by diluting them with 1.7 M galactose. To vitrify the embryos, they were exposed to 2.0 M EG for 5 min and then were pipetted directly into short columns of 8.0 M EG-PVP contained within (1.25-ml plastic straws and separated from long columns of 1.7 M galactose by an air bubble. The straws were plunged directly into LN2. After the straws were warmed rapidly in a 25 degrees C water bath, the embryos were immediately mixed with galactose within the straws by shaking them vigorously to mix the contents. In sequential experiments, three methods were used to dilute the CPA solutions. Method 1: Embryos in the EG-PVP-galactose mixture were expelled from the straws and rinsed and cultured in modified CZB medium (mCZB). Method II: Embryos in the mixture were placed briefly into 1.5 M EG and then rinsed and cultured in mCZB. Method III: Embryos in the mixture were rinsed in 1.0 M EG and then in 0.5 M EG and finally rinsed with mCZB and cultured. After 48 h in culture, the respective percentages of survival of embryos vitrified as BL, ExB, or HB were: Method I, 21, 32, and 13%; Method II, 9, 40, and 24%; Method III, 35, 85, and 71%. Of 20 additional ExB vitrified embryos diluted by Method III and transferred into a recipient, four developed into live piglets; two other recipients failed to litter although one had been pregnant for 65 days. These results demonstrate that porcine embryos can be successfully cryopreserved by rapid cooling in EG-PVP and by careful dilution of the CPA after warming.

Hydrogen peroxide enhances phagocytic activity of ameboid microglia

Microglia are considered to serve as a guardian of the brain. In achieving this task, they have been observed to transform into a reactive form and then an ameboid form. Several substances are implicated in the control of such behavior. We examined the effect of hydrogen peroxide on cultured microglia of ameboid form obtained from the fetal rat brain employing video-enhanced contrast-differential interference contrast microscopy. Microglia harvested from the culture bottle were observed to float in a spherical shape with abundant filopodia on the surface. However, on coming into contact with the glass surface of a cover slip, they immediately transformed into an ameboid form. The microglia spread themselves out, surrounded by thin transparent lammellipodia, which would not be clearly observable by either light microscopy or electron microscopy. In a concentration-dependent fashion, 10(-3)-10(-1) M hydrogen peroxide solution enhanced the ruffling process of the lamellipodia and formation of vesicles (phagosomes), which displayed a typical phagocytotic form. It is concluded that an increase in free radicals in ischemic tissue tends to facilitate the phagocytosis of ameboid microglia as macrophages.

Pulmonary arteriovenous fistula: long-term results of percutaneous transcatheter embolization with spring coils

PURPOSE

The aim of this study was to assess the effectiveness of percutaneous treatment of PAVFs through the results of long-term follow-up.

PATIENTS AND METHODS

Transcatheter embolization of PAVFs using spring coils was performed in seven patients (six women and one man) with nine PAVFs, between 1989 and 1995, who were followed up at least one year. The size of the nine PAVFs ranged from 4 mm to 70 mm in diameter (mean 26 mm). Two fistulas were huge, 70 x 45 mm and 60 x 65 mm in diameter. Embolization was performed twice in three patients and once in four patients. In the two patients with huge PAVFs, after anchoring metallic "spiders" into the feeding artery, the largest coils were positioned and entangled with the "spider" followed by the placement of smaller coils to fill in the center of the feeding artery.

RESULTS

No severe complications were seen in the short-term follow-up. Arterial oxygen pressure improved in all patients with low oxygen pressure. Five patients with seven fistulas, six of which disappeared on chest X-ray film, are still alive after follow-up ranging from one year and 10 months to seven years and nine months. The two patients with huge fistulas died more than one year after treatment, one of hemoptysis of the contralateral lung and the other of pulmonary fibrosis.

CONCLUSION

Complete embolization of a medium-sized feeding artery can cure this anomaly.

Expression of aggression attenuates both stress-induced gastric ulcer formation and increases in noradrenaline release in the rat amygdala assessed by intracerebral microdialysis

The effects of an aggressive biting response on stress-induced noradrenaline (NA) release in the rat amygdala and gastric ulcer formation were studied with an intracerebral microdialysis technique. Rats were exposed to a 60-min period of cold restraint stress with or without being allowed to bite a wooden stick. They were sacrificed 100 min after release from stress to investigate gastric ulcer formation. Cold-restraint stress increased NA release to 304 +/- 22.3 and 206 +/- 23.8% of basal levels (mean +/- SEM) in the nonbiting and biting groups, respectively. The stress-induced increases in NA release in the nonbiting group were significantly higher than those in the biting group. In the nonbiting group, significant increases in NA release continued for 80 min after release from stress; however, NA levels in the biting group recovered to basal levels immediately after the cessation of stress. Although many severe gastric lesions with bleeding were found in the nonbiting group, fewer gastric lesions without bleeding were found in the biting group. The cumulative length of gastric lesions in the nonbiting group and in the biting group was 26.2 +/- 7.4 and 6.8 +/- 3.9 mm (mean +/- SEM), respectively. The mean number of ulcers in the nonbiting group and the biting group was 11.8 +/- 1.3 and 1.8 +/- 0.7 (mean +/- SEM), respectively. Both the cumulative length of ulcers and the number of ulcers were significantly lower than those seen in the nonbiting group. These findings strongly suggest that expression of aggression during stress exposure attenuates not only stress-induced increases in NA release in the rat amygdala but also gastric ulcer formation consequent to stress.

Roles of macrophages in programmed cell death and remodeling of tail and body muscle of Xenopus laevis during metamorphosis

Examination was made of the involvement of macrophage phagocytosis in programmed cell death of tail and body muscle of the frog, Xenopus laevis, during metamorphosis by electron microscopy and immunohistochemical analysis. Electron microscopic observation revealed that macrophages were often found to be present in body and tail muscles at the most active stage of metamorphosis and to actively phagocytose apoptotic muscle fragments. Developmental changes in macrophages were examined using the macrophage-specific antibody, HAM56. Macrophages initially appeared in the early climax stage (stage 59), when the triiodothyronine (T3) level was high, increased rapidly during the process of muscle cell death, and assumed their greatest number at the late climax stage (stage 63/64). They decreased after stage 65/66, with a decrease in T3. Distribution and change in the number of macrophages were the same as those of muscle apoptotic bodies (sarcolytes) during metamorphosis, which suggests an interactive mechanism between macrophages and dying muscle cells. For clarification of this, study was made of the expression of HAM56 antigens that were X. laevis homologs of mouse attachmin, non-specific adhesion proteins in macrophages. The expression of HAM56 antigens in macrophages was found to increase with macrophage phagocytosis at the late climax stage, thus, macrophage differentiation would appear to take place during metamorphosis and HAM56 antigens may be essential for macrophage-dying muscle cell interactions.

CpG distribution patterns in methylated and non-methylated species

To characterize the extent of DNA methylation and its possible biological roles in a wide variety of organisms, we have analyzed gene sequences extracted from the GenBank database. Sequences of both methylated and non-methylated species were used for comparative analysis. The local CpG dinucleotide distribution near the 5' ends of genes as well as the degree of overall CpG suppression/depletion in the entire gene region were examined in all complete gene sequences for each species. We show that the distribution patterns of CpG near the 5' region of genes differ among vertebrates, invertebrates, plants and bacteria. CpG island-like peaks in CpG O/E (observed/expected ratio) were observed not only in methylated species, but also in non-methylated species. In methylated non-vertebrates, overall CpG O/E values were lower, and peaks in the CpG profile of 5' regions were larger than in non-methylated species. We discuss the implications of such biases with respect to DNA methylation.

Alu elements as an aid in deciphering genome rearrangements

Genomic rearrangements result in genomic duplications that lead to the generation of more complex genomes. Some attempts have been made to trace duplication histories of different loci using Alu elements because of their large population in primate genomes (Chen et al., 1989; Mnuková-Fajdelová et al., 1994). In this short report, using the human growth hormone locus as an example, we demonstrate the usefulness of Alu repetitive elements in computer sequence analyses when tracing duplication histories. Information on subfamily classification, direction, arrangements, Poly(A) tails and direct repeats can aid our understanding of genome rearrangements.

Cloning of the cDNA for a mouse homologue of human PHBP: a novel hyaluronan-binding protein

The cDNA which encodes the mouse counterpart of human plasma hyaluronan-binding protein (PHBP) was isolated and characterized. The clone contained an insert of 2153 bp, which contained the 1674-bp open reading frame coding for a polypeptide of 558 amino acid residues. The amino acid sequence of mouse PHBP predicted from the nucleotide sequence of cDNA shows reasonable homology to that of human PHBP. Like human PHBP, the amino acid sequence predicted from the nucleotide sequence of mouse PHBP cDNA exhibited significant homology to that of human hepatocyte growth factor activator (HGFA).