Efficacy of maternal serum screening in the prenatal detection of fetal chromosome abnormalities in Japanese women

OBJECTIVE

This prospective study assesses the efficacy of maternal serum screening for use in prenatal diagnosis of fetal anomaly and chromosome imbalance in Japanese women.

METHODS

Maternal serum alpha-fetoprotein, human chorionic gonadotropin, and unconjugated estriol were measured in 1,055 singleton pregnant women between 14 and 20 weeks of gestation. A calculated risk for trisomy 21 of >/=1/299 or alpha-fetoprotein >/=2.5 multiples of the median was adopted as positive.

RESULTS

Three hundred and seventy-eight of the 1, 055 women screened (35.8%) were identified as positive. Sensitivity, false-positive rate, and positive predictive value in women aged <35 years were 60.0, 10.6, and 6.8%, respectively, and these values were 87.5, 49.3, and 4.2%, respectively, in women aged >/=35 years. The false-positive rate in women aged <35 years was significantly lower than that for women aged >/=35 years (p < 0.001). Chromosomal abnormalities were identified in 21 cases, including 10 with trisomy 21, 5 with trisomy 18, 2 with trisomy 13, and 4 with other chromosomal disorders. Seventeen of the 21 cases (81.0%) showed screen-positive results, and among these all 10 cases with trisomy 21 were detectable. Two cases with trisomy 18, 1 with trisomy 13 and 1 with isochromosome X showed extremely low human chorionic gonadotropin levels (0.4 +/- 0.1 multiples of the median, mean +/- SE), although they were screen negative. Of the 264 women who did not undergo amniocentesis, none had any clinical findings consistent with aneuploidy after birth.

CONCLUSIONS

Our results suggest that the evaluation of each serum marker, as well as of the calculated risk, was significantly important in the prenatal detection of fetal aneuploidy.

An efficient method for production of uridine 5'-diphospho-N-acetylglucosamine

Uridine 5'-diphospho-N-acetylglucosamine (UDP-GlcNAc) has been synthesized by a yeast-based method from 5'-UMP and glucosamine, in which yeast cells catalyze the conversion of 5'-UMP to 5'-UTP and provide enzymes involved in UDP-GlcNAc synthesis using 5'-UTP and glucosamine as substrates. However, this conventional method is not suitable for practical production of UDP-GlcNAc because of the low yield of the product. We found that the yqgR gene product of Bacillus subtilis, which has been identified as a glucokinase, can catalyze the phosphorylation of N-acetylglucosamine (GlcNAc) to give GlcNAc-6-phosphate, an intermediate of UDP-GlcNAc biosynthesis. The addition of the yqgR gene product to the yeast-based reaction system enabled us to synthesize UDP-GlcNAc using GlcNAc in place of glucosamine. The addition of two enzymes, GlcNAc-phosphate mutase and UDP-GlcNAc pyrophosphorylase, increased the yield of UDP-GlcNAc. Using this novel method, UDP-GlcNAc was produced at an amount of 78 mM from 100 mM 5'-UMP and 100 mM GlcNAc.

Dumb-bell-type teratoma in the lumbar spine

We report a case of a lumbar teratoma in a 50-year-old woman. The teratoma showed a dumb-bell-type expansion at the level of the left L3/4 foramen with massive erosion of the L3 vertebral body. MRI revealed inhomogeneous signal changes in the tumor, which were histologically compatible with a mixture of bone, muscle, fat, and cyst containing sebaceous material. Complete resection of the tumor and spinal arthrodesis with pedicle screw fixation was necessary to obtain stability of the affected spinal segment.

Total spondylectomy for solitary spinal metastasis of the thoracolumbar spine: a preliminary report

Eight cases of solitary spinal metastasis with neurological deficit in thoracolumbar spine in which total en bloc spondylectomy (TS) was performed by bisecting the affected vertebra through both pedicles using fine thread wire saws were reviewed. Patient age ranged from 40 to 78 (mean, 62) years. Primary lesions were in the lung (2), kidney (2), thyroid (3) and prostate (1). TS was performed through a posterior approach in 5 cases (T6-7, T12, L2, L2 and L2-3) and through a one-stage anterior and posterior combined approach in the others (L2, L3 and L4). The spine was reconstructed with a ceramic vertebral prosthesis and a pedicle screw fixation system in 5 cases, and with augmented anterior spinal instruments in 3 cases. There were neither surgical complications nor surgical mortality. All patients became ambulatory and pain-free after surgery. Histologically, a marginal surgical margin was achieved in only one case. The other 7 cases had intralesional margin at the osteotomized pedicles. Four patients died from causes unrelated to local recurrence 4 to 44 (mean, 19) months after surgery. Effectiveness of surgery was maintained until death in all 4 of these patients. Asymptomatic local recurrence occurred in 2 patients with renal cancer at 10 and 33 months after surgery. These preliminary results suggest that TS for solitary spinal metastasis can achieve good control of local recurrence without major complications and is clinically acceptable surgery.

Structural study of anhydrous tendon chitosan obtained via chitosan/acetic acid complex

The molecular structure and packing arrangement of anhydrous tendon chitosan was determined by the X-ray fibre diffraction method together with the linked-atom least-squares refinement technique. The specimen was prepared from chitosan/acetic acid complex which was obtained by exposing tendon chitosan to acetic acid vapour at room temperature for several days. There is high degree of orientation and crystallinity compared with the specimen obtained by the annealing method. Two chitosan chains are present in an orthorhombic unit cell of dimensions a = 8.26(2), b = 8.50(1), c (fibre axis) = 10.43(2) A and space group P2(1)2(1)2(1). The 2-fold helical chain is stabilised by O3 triple bond O5 hydrogen bond with the gt orientation of O6. There are direct hydrogen bonds (N2 triple bond O6) between adjacent chains along the a-axis, which makes a sheet structure parallel to the ac-plane. On the other hand, no hydrogen bond is found between the sheets.

A novel Na+ and Ca2+ channel blocker, T-477, prevents brain edema following microsphere-induced permanent occlusion of cerebral arterioles in rats

One of the most common acute complications of stroke is brain edema. Treatment of edema is recommended when the condition of the patients is deteriorating. The present study was undertaken to evaluate the effect of T-477 [(R)-(+)-2-(4-chlorophenyl)-2,3-dihydro-4-diethyl aminoacetyl-4H-1,4-benzorthiazine hydrochloride], a novel neuronal Na+ and Ca2+ channel blocker, on brain edema in rats. Cerebral ischemia was induced by intra-arterial infusion of 1000 microspheres into the forebrain of freely moving rats, resulting in brain edema. T-477 was intravenously infused continuously for 24 h or twice for 3 h with a 3-h interval between infusions immediately after microsphere injection. T-477 dose-dependently inhibited the increase in brain water content by both infusion procedures; the inhibition was statistically significant at doses of 25 mg/kg per 24 h and 14 mg/kg per 9 h. Additionally, infusion of T-477 at a dose of 14 mg/kg per 9 h significantly inhibited the decrease in K content and the increase in Ca content of the forebrain. In conclusion, T-477 prevents brain edema following microsphere-induced cerebral embolism in rats.

Induction of antenatal periventricular leukomalacia by hemorrhagic hypotension in the chronically instrumented fetal sheep

OBJECTIVES

Our purpose was to determine whether systemic hypotension induced by rapid withdrawal of fetal blood would induce periventricular leukomalacia in the brain of premature fetal sheep.

STUDY DESIGN

At 113 days' gestation, systemic hypotension (mean blood pressure <30 mm Hg) was induced by withdrawing approximately 35% of the fetoplacental blood volume in the hemorrhage group (n = 6), whereas in the control group (n = 4) isovolemic exchange transfusion was carried out. Six days after the insult, fetal brains were removed and processed for histologic analysis.

RESULTS

Five of the 6 fetuses in the hemorrhage group exhibited periventricular white-matter lesions, consisting of nodular coagulation necrosis or diffuse axonal swellings or both. No abnormal findings other than these lesions were detected in the fetal brains in either experimental group.

CONCLUSION

Hemorrhagic hypotension antenatally induced brain lesions similar to those of periventricular leukomalacia, suggesting that it is an essential element in the pathogenesis of periventricular leukomalacia in premature fetuses.

Morphological aspects of ectopia cordis: four case reports and a review of the literature

Ectopia cordis is a rare congenital anomaly. We present 4 cases of ectopia cordis, 1 of which is the first report of an affected fetus in a triplet pregnancy. The morphological relationship between the types of ectopia cordis and their outcomes were investigated in all 4 cases. In addition, the literature on ectopia cordis in Japan was reviewed and discussed.

Posterior lumbar interbody fusion: a retrospective study of complications after facet joint excision and pedicle screw fixation in 148 cases

We retrospectively evaluated neurological and other complications related to posterior lumbar interbody fusion (PLIF) performed by facet joint excision and pedicle screw fixation, in 148 consecutive patients with degenerative disorders. Their mean age at surgery was 59 (19-80) years. The mean follow-up period was 3 (2-6.5) years. Overall, 91 complications in 75 cases were observed. Although no permanent neural damage was detected, transient neural palsy occurred in 8% of the cases. Dural tear, partial misplacement, loosening, breakage of the pedicle screw and loss of correction were seen in 6, 6, 4, 1 and 1 of the cases, respectively. Deep infection of the fused segment developed in 2 cases. We conclude that PLIF, performed by facet joint excision and pedicle screw fixation, demonstrated a very low incidence of osteosynthesis failure, such as screw loosening, breakage and loss of correction. However, the high incidence of other complications, particularly neurological impairment, is still a disadvantage of this technically-demanding procedure.

Recent trends in the prevalence of Down syndrome in Japan, 1980-1997

The aims of the present study were to determine recent trends in the prevalence of Down syndrome (DS) in Japan, and to determine whether recent changes in demographic and social habits and access to prenatal diagnosis have influenced the livebirth rates of DS. Livebirth statistics indicate that the birth rate in Japan has decreased for women in their 20s and has increased for those in their 30s and 40s. During an 18-year period between 1980 and 1997, 1,299 consecutive DS infants were born among a total of 2,232,694 births, a rate corresponding to approximately 10% of all births in Japan over the same period. The increasing risk of DS with advancing maternal age was confirmed. The overall prevalence was 5.82 DS births per 10,000 livebirths (8.3-9.7 per 10,000 after correction according to the estimated ascertainment ratio: 60-70%). The prevalence rate by year of child birth represents a statistically significant increase (P = 0.001). In conclusion, recent trends in the prevalence of DS in Japan from 1980 to 1997 failed to show a consistent tendency to decrease, probably because of the concomitant increase in pregnancy in advanced maternal age.

Crystal structure of Thermoactinomyces vulgaris R-47 alpha-amylase II (TVAII) hydrolyzing cyclodextrins and pullulan at 2.6 A resolution

The crystal structure of Thermoactinomyces vulgaris R-47 alpha-Amylase II (TVAII) has been determined by multiple isomorphous replacement at 2.6 A resolution. TVAII was crystallized in an orthorhombic system with the space group P212121 and the cell dimensions a=118.5 A, b=119.5 A, c=114.5 A. There are two molecules in an asymmetric unit, related by the non-crystallographic 2-fold symmetry. Diffraction data were collected at 113 K and the cell dimensions reduced to a=114.6 A, b=117.9 A, c=114.2 A, and the model was refined against 7.0-2.6 A resolution data giving an R-factor of 0.204 (Rfree=0.272). The final model consists of 1170 amino acid residues (two molecules) and 478 water molecules with good chemical geometry. TVAII has three domains, A, B, and C, like other alpha-amylases. Domain A with a (beta/alpha)8 barrel structure and domain C with a beta-sandwich structure are very similar to those found in other alpha-amylases. Additionally, TVAII has an extra domain N composed of 121 amino acid residues at the N-terminal site, which has a beta-barrel-like structure consisting of seven antiparallel beta-strands. Domain N is one of the driving forces in the formation of the dimer structure of TVAII, but its role in the enzyme activity is still not clear. TVAII does not have the Ca2+ binding site that connects domains A and B in other alpha-amylases, rather the NZ atom of Lys299 of TVAII serves as the connector between these domains. TVAII can hydrolyze cyclodextrins and pullulan as well as starch. Based on a structural comparison with the complex between a mutant cyclodextrin glucanotransferase and a beta-cyclodextrin derivative, Phe286 located at domain B is considered the residue most likely to recognize the hydrophobic cavity of cyclodextrins. The active-site cleft of TVAII is wider and shallower than that of other alpha-amylases, and seems to be suitable for the binding of pullulan which is expected not to adopt the helical structure of amylose.

Crystal structure of the E166A mutant of extended-spectrum beta-lactamase Toho-1 at 1.8 A resolution

Bacterial resistance to beta-lactams is mainly due to the production of beta-lactamase. Especially through the production of extended-spectrum beta-lactamases (ESBLs), bacteria have acquired resistance not only to penicillins, but also to expanded-spectrum cephems. Here, we describe the crystal structure of the E166A mutant of class A beta-lactamase Toho-1 at 1.8 A resolution, the first reported tertiary structure of an ESBL. Instead of the wild-type enzyme, a mutant Toho-1, in which Glu166 was replaced with alanine, was used for this study, because of the strong tendency of the wild-type enzyme to form twinned crystals. The overall structure of Toho-1 is similar to the crystal structures of non-ESBLs, with no pronounced backbone rearrangement of the framework. However, there are some notable local changes. First, a difference in the disposition of an arginine residue, which is at position 244 in non-ESBLs but at position 276 in Toho-1 and other ESBLs, was revealed and the role of this arginine residue is discussed. Moreover, changes in the hydrogen-bonding pattern and in the formation of the hydrophobic core were also observed near the Omega loop. In particular, the lack of hydrogen bonds in the vicinity of the Omega loop could be a cause of the extended substrate specificity of Toho-1. Through the generation of a model for the enzyme-substrate complex, a conformational change of Toho-1 occurring on complex formation is discussed based on the active-site cleft structure and the substrate profile.

Structure analysis of a collagen-model peptide with a (Pro-Hyp-Gly) sequence repeat

The crystal structure of a triple helical peptide (Pro-Hyp-Gly)10 has been determined at 1.9 A resolution. Single crystals grown by the hanging drop method, diffracted to a resolution of 1.8 A. The polymer-like structure of the triple helical repeat Pro-Hyp-Gly was in accordance with the 7/2 model proposed for collagen and very similar to the previously determined structure with a Pro-Pro-Gly sequence repeat. The solvent structure was also very similar to that previously observed, showing similar hydration patterns, but different crystal packing. The presence of hydroxyproline did not have any effect on the molecular structure or the hydration structure. This is in accordance with the recent finding that the inductive effect of the hydroxyl group attached to the Cgamma atom of hydroxyproline enhances collagen stability rather than the extensive water network.

Estimated nutritional intake based on the reference growth curves for extremely low birthweight infants

BACKGROUND

Although the optimal goal of extremely low birthweight (ELBW) infants has been debated, it can be argued that the best nutritional strategy for ELBW infants is one which achieves better growth while preventing neurological sequelae due to nutritional inadequacy, even if it does not mimic fetal growth. Our aim is to propose an advisable and practically feasible nutritional intake for ELBW infants.

METHODS

We retrospectively investigated the nutritional intake in 16 ELBW infants (gestational age 26.7 weeks, birthweight 879.6 g), who exceeded the standard growth curves for Japanese infants of ELBW. We also analyzed the nutritional composition of human milk from 15 mothers delivering before term (PT milk) until the 12th week of lactation. The nutritional intake was calculated according to the composition of the parenteral and enteral regimen.

RESULTS

The infants tolerated more than 100 mL/kg per day of milk until the fourth week of life. An average weight gain of more than 15 g/kg per day was achieved by the sixth week. An advisable nutritional intake capable of sustaining ELBW infants in a stable growing phase was calculated as the sum of the mean plus 1SD of the daily nutritional intake.

CONCLUSIONS

To exceed the ordinary growth curves for ELBW Japanese infants, it was suggested that more than 100 mL milk/kg per day could be fed until the fourth week of life, while the advisable daily intake of nutrients after six weeks of life should be as follows: water 160 mL/kg, protein 3.2 g/kg, fat 7.4 g/kg, carbohydrate 12.8 g/kg, energy 544 kJ/kg, the following minerals in mg/kg: sodium 45, chloride 82, potassium 110, calcium 140, phosphorus 70, magnesium 11, zinc 0.5 and copper at 60 micrograms/kg. Further studies will be needed to confirm the safety and effectiveness of this advisable intake for ELBW infants.

Primary Non-Hodgkin's Lymphoma of the Male Breast: A Case Report

A 69-year-old Japanese man presented with bilateral gynecomastia and a soft, mobile and clearly defined mass beneath the left nipple. A round radiopaque masswas revealed on mammography. The tumor was homogeneous, hypoechoic and measured2.4 x 3.9 cm on ultrasonography. Based on a diagnosis of malignant lymphoma by needle aspiration cytology, a modified radical mastectomy with ipsilateral axillary lymph node dissection was performed. Malignant diffuse large B-cell type lymphoma was diagnosed histologically. Whole body examinations revealed no evidenceof other tumors. Three courses of adjuvant CHOP therapy were subsequently performed. The patient is free of recurrence 12 months after surgery. Primary non-Hodgkin's lymphoma (NHL) of the male breast is extremely rare. The occurrence of lymphoma in this patient could be related to elevated estrogen levels.

Crystal structure analysis of collagen model peptide (Pro-pro-Gly)10

Single crystals of (Pro-Pro-Gly)10 were grown by the hanging drop method. The crystals diffracted to a resolution of 1.8 A. In the crystals the polypeptides form triple helices that aggregate end-to-end mediated by the solvent molecules, with the basic repeat being 20 A along the helical axis. Analysis of the 20 A structure of (Pro-Pro-Gly)10 using data up to a resolution of 1.9 A revealed that the overall structure is in accordance with the 7/2 model proposed for collagen. The three strands are held together by the (Gly) N-H O (Pro-X) hydrogen bond interactions, and additional stability is provided by the (Pro-Y) Calpha -H O (Pro-X) hydrogen bonding interactions.

Prenatal identification of mos 45,X/46,X,+mar in a normal male baby by cytogenetic and molecular analysis

We report a case of mos 45,X/46,X,+mar, diagnosed prenatally by amniocentesis, whose physical examination, including external and internal organs, along with serum testosterone values were normal five years after delivery. The mosaic karyotype was seen in 146 of 240 cells examined (amniotic fluid cells, 110/65; placental chorionic villi: 5/4; cord blood, 21/81; cultured skin fibroblasts, 10/90) from 386 metaphases, and the marker chromosome appeared as a small non-fluorescent acrocentric chromosome. All autosomes appeared normal, and no normal Y chromosome could be demonstrated. Analysis of 26 Y-chromosome loci by molecular techniques such as PCR, Southern analysis using multiple Y-specific DNA probes, and Hae III restriction endonuclease assessment of male-specific repeated DNA in the heterochromatic region of the Y chromosome, and fluorescence in situ hybridization (FISH), revealed the marker was derived from a Y chromosome including p terminal to q11.23, and paracentric inversion in the remaining Y long arm. The formation of testes can be considered as existence of SRY (sex-determining region of Y) as a testis-determining factor. The present report illustrates the importance of FISH and molecular techniques as a complement to cytogenetic methods for accurate identification and characterization of chromosome rearrangements in prenatal diagnosis.

Intraperitoneal administration of cytomegalovirus hyperimmunoglobulin to the cytomegalovirus-infected fetus

Twenty-five percent of cytomegalovirus (CMV)-infected fetuses had sequelae and 8% of those in the recurrent-infected group had sequelae. There is no report yet on the fetal therapy for CMV infections. A Japanese pregnant woman with intrauterine fetal CMV infection diagnosed at 26 weeks of pregnancy is presented. CMV culture of amniotic fluid was positive. A CMV DNA assay using the polymerase chain reaction method of the cord blood and the amniotic fluid was positive during the pregnancy; however, testing for fetal serum CMV-specific IgM was negative. The CMV IgG titer of fetal serum at 27 weeks of pregnancy was a third of that of the maternal serum. CMV hyperimmunoglobulin was injected into the fetal abdominal cavity at 28 and 29 weeks of pregnancy. A second administration of CMV hyperimmunoglobulin increased the titer of CMV IgG in the fetal circulation. At birth, the urine culture was positive for CMV. However, CMV DNA of the ascites became negative. A brain CT scan performed 2 weeks after birth revealed some small calcifications beside the right ventricle. CMV hyperimmunoglobulin injection to the fetal abdominal cavity has been shown to increase the IgG in the fetal serum. This is the first report of fetal therapy of congenital CMV infection.

Distribution pattern and risk factors of pelvic and para-aortic lymph node metastasis in epithelial ovarian carcinoma

The distribution of lymph node metastasis and the clinicopathologic risk factors for nodal involvement in ovarian carcinoma need to be clarified based on systematic lymph node dissection. We studied 115 patients with ovarian carcinoma who underwent systematic pelvic and para-aortic lymph node dissection between 1987 and 1997. The incidence and distribution of lymph node metastasis are described and the clinico-pathologic risk factors for nodal involvement are investigated. Based on the occurrence of lymph node metastasis in the early stages, the incidence of solitary node involvement and the distribution of lymph node metastasis, we conclude that the primary site of nodal involvement in ovarian carcinoma is the para-aortic node (PAN), especially PAN superior to the inferior mesenteric artery (IMA). By univariate analysis, clinical stage, histologic type (mucinous vs. others), grade, multiple peritoneal metastases, peritoneal cytology, volume of ascites and serum CA125 level were correlated with overall incidence of lymph node metastasis. By performing a multivariate analysis with the clinical stage excluded, it was revealed that grade and peritoneal cytology were independent factors for PAN metastasis (p < 0.0025 and < 0.001, respectively) and that multiple peritoneal metastases and PAN metastasis were significant predictors of pelvic node metastasis (p < 0.01 and < 0.005, respectively). In conclusion, the PANs superior and inferior to IMA should be explored in staging of ovarian carcinoma that appears to be confined to the ovaries. To determine accurately the extent of disease, both the para-aortic and pelvic areas may need to be sampled or dissected in the case of ovarian carcinoma involving the peritoneal surfaces.

A selective inhibitor of intestinal ACAT, EAB309 suppresses both intestinal and hepatic cholesterol output and stimulates chylomicron removal

The effect of a novel inhibitor of acylcoenzyme A:cholesterol acyltransferase (EC 2.3.1.26, ACAT), EAB309 (EAB) on plasma lipid metabolism was studied in cholesterol-fed rats. Orally administered EAB was not detected in the portal vein or the liver but distributed exclusively in the intestine, suggesting that this agent selectively inhibits intestinal ACAT. The rats were fed with either a cholesterol-diet or a cholesterol-diet containing 0.005% EAB (w/w) ad. libium for three weeks. ACAT activity in intestinal microsomes was significantly inhibited in EAB-treated rats. Hepatic ACAT activity was also decreased in EAB-treated rats, however, this was attenuated by the addition of excess cholesterol to the liver microsome, indicating that substrate availability is tightly associated with this enzyme's activity and the inhibition of hepatic ACAT by EAB is not direct. Incorporation of [3H]-cholesterol to cholesteryl ester (CE) in mesenteric lymph were markedly suppressed by EAB treatment. Chylomicrons (CMs) were doubly labeled with [3H]-vitamin A and [14C]-triglyceride (TG) in EAB-treated or non-treated rats and injected into normal chow-fed rats. The CMs from EAB-treated rats were cleared faster from the plasma and taken up more by the liver compared with the CMs from non-treated rats. The content of CE in newly secreted VLDL was remarkably decreased by EAB treatment without affecting TG output. These results demonstrate that EAB, a novel inhibitor of intestinal ACAT, significantly suppresses both intestinal and hepatic CE output and stimulates CM removal. This suggests that the inhibition of intestinal ACAT can subsequently suppress hepatic ACAT by decreased CE delivery from the intestine to the liver.

Anesthetic potency and cardiopulmonary effects of sevoflurane in goats: comparison with isoflurane and halothane

The anesthetic potency and cardiopulmonary effects of sevoflurane were compared with those of isoflurane and halothane in goats. The (mean +/- SD) minimal alveolar concentration (MAC) was 0.96 +/- 0.12% for halothane, 1.29 +/- 0.11% for isoflurane, and 2.33 +/- 0.15% for sevoflurane. Cardiopulmonary effects of sevoflurane, halothane and isoflurane were examined at end-tidal concentrations equivalent to 1, 1.5 and 2 MAC during either spontaneous or controlled ventilation (SV or CV). During SV, there were no significant differences in respiration rate, tidal volume and minute ventilation between anesthetics. Dose-dependent decreases in both tidal volume and minute ventilation induced by halothane were greater than those by either sevoflurane or isoflurane. Hypercapnia and acidosis induced by sevoflurane were not significantly different from those by either isoflurane or halothane at 1 and 1.5 MAC, but were less than those by halothane at 2 MAC. There was no significant difference in heart rate between anesthetics during SV and CV. During SV, all anesthetics induced dose-dependent decreases in arterial pressure, rate pressure product, systemic vascular resistance, left ventricular minute work index and left ventricular stroke work index. Systemic vascular resistance with isoflurane at 2 MAC was lower than that with sevoflurane. During CV, sevoflurane induced dose-dependent circulatory depression (decreases in arterial pressure, cardiac index, rate pressure product, systemic vascular resistance, left ventricular minute work index and right ventricular minute work index), similar to isoflurane. Halothane did not significantly alter systemic vascular resistance from 1 to 2 MAC.

Seminoma in a postmenopausal woman with a Y;15 translocation in peripheral blood lymphocytes and a t(Y;15)/45,X Turner mosaic pattern in skin fibroblasts

We report an unusual case of a 55 year old Japanese woman with a seminoma but relatively normal menses. The patient was a phenotypic female with late onset menarche (18 years of age), who was amenorrhoeic for the first year, followed by menses of one to three days' slight flow with dysmenorrhoea, but an otherwise normal menstrual history. A typical seminoma was removed from the left adnexal region and an immature testis was identified separately as an associated right adnexal mass. Repeated karyotypic studies on peripheral blood lymphocyte cultures showed only 46,X,-Y,t(Y;15)(q12;p13). Cytogenetic examination of the patient's younger brother, who had fathered three healthy children, showed an identical karyotype. Mosaicism of 46,X,-Y,t(Y;15)(q12;p13)/45,X cell lines was found in skin samples from the patient's elbow and genital regions, although there were no clinical stigmata of Turner syndrome. An androgen receptor binding assay of cultured genital skin fibroblasts was negative. Molecular analysis using Southern blot hybridisation, PCR, and direct DNA sequencing showed that neither the patient nor her brother had a detectable deletion or other abnormalities of Y chromosome sequences, including the SRY (sex determining region of the Y chromosome) gene sequence. These findings suggest that Turner mosaicism of the 45,X cell line may have contributed to this atypical presentation in an XY female, although we cannot exclude abnormalities of other genes related to sex differentiation.

Time-dependent changes in the ischemic forebrain following the microsphere-induced permanent occlusion of cerebral arterioles in rats

To evaluate the progression of brain edema without modification by the effect of anesthetics, we examined the local and permanent ischemia model in unanesthetized rats. The forebrain embolism was induced by intra-arterial infusion of microspheres of 50-microm diameter in freely moving rats. From 2 to 48 hr following the injection, the water-, Na- and Ca-contents progressively increased while the K content decreased in the microsphere-injected hemisphere. After the 3rd day, the water- and Na-contents gradually decreased and returned to the normal level on the 14th day. In contrast, the Ca level remained elevated even on the 56th day. The animals showed signs of neurological deficits 24 hr after the injection. In histopathological examination, large infarct areas were present in the microsphere-injected hemisphere after 24 to 48 hr. One to two weeks later, the lateral ventricle was expanded. Eight weeks after the injection, the ventricle remained expanded and newly developed infarct areas were observed in a scattered pattern around the fibrotic area. The results show the close correlation between the development of edema and the increase/decrease of Na/K contents from the onset to the recovery from edema, and their changes are similar to those in human stroke. This model enables us to evaluate not only the acute ischemic insult but also the chronic changes of the forebrain following the stroke.

[Use of the radial artery graft in coronary artery bypass grafting: harvesting technique and spasm prevention]

The use of radial artery (RA) in coronary artery bypass grafting (CABG) has been increasing recently as a revival. In this report, we describe several practical suggestions for improving patency rate of the graft. Between April of 1997 and February of 1998, 41 CABGs were performed using RA graft, totalling 56 anastomoses. The early patency rate of the graft has been 100% (graft: 38/38, anastomosis: 53/53). Harvesting technique: with the use of Harmonic Scalpel, it is possible to atraumatically harvest the vessel in a short time. Although longitudinal fasciotomy of the adventitia has been recently reported to be effective in releasing spasm, the nature of the vessel raise concern that the fasciotomy may even induce spasm. We hypothesize that leaving the adventitia intact, preserving vasa vasorum, rather than performing fasciotomy leads to improvement of long-term patency. Spasm prevention: we consider the body temperature to be the most important factor. Therefore, we utilize normothermic cardiopulmonary bypass (CPB). Another important factor is that the arterial CO2 is kept at a high level during CPB. For dilation of RA graft, milrinone is used instead of papaverine. For the intra- and postoperative management, intravenous continuous administration of diltiazem was changed to nicorandil. Technically, essential resolution for improvement of patency rate is either to allow for large proximal anastomosis, or to make sequential anastomosis with another coronary artery which has a good run off. For these purposes, the proximal anastomosis on the ascending aorta seems to have the advantage over placing it on ITA.

Prenatal diagnosis of limb-body wall complex

OBJECTIVE

To evaluate prenatal diagnosis of limb-body wall complex (LBWC) by ultrasonography in eight cases.

STUDY DESIGN

The diagnosis was based on two of the following: exencephaly/encephalocele with facial clefts, thoracoschisis and/or abdominoschisis and limb defect. The ultrasonographic findings were compared with the autopsy findings in each case.

RESULTS

The average weeks of gestation at which malformations were diagnosed by ultrasonography was 21.7 +/- 4.7 (mean +/- SD, n = 8). All eight fetuses were diagnosed as having characteristic abnormalities and six of them as having scoliosis by ultrasonography. Four of the eight were examined for maternal serum alpha-fetoprotein (MSAFP); the levels exceeded 2.5 multiples of the mean according to the standard value at our hospital. Chromosomal analysis was performed for six cases and revealed that they were normal in karyotype. All eight cases showed abdominoschisis, scoliosis and abnormalities of the lower extremities. A single umbilical artery was present in seven cases (87.5%), and a short umbilical cord was present in seven (87.5%).

CONCLUSION

Ultrasonographic detection of abdominoschisis, scoliosis abnormalities of the lower extremities, a single umbilical artery and a short umbilical cord is important for the prenatal diagnosis of LBWC. An extremely elevated level of MSAFP is also indicative of the complex.

Alcohol-related cancers and aldehyde dehydrogenase-2 in Japanese alcoholics

Aldehyde dehydrogenase-2 (ALDH2) eliminates most of the acetaldehyde produced during alcohol metabolism. In some drinkers, a mutant ALDH2 allele contributes to diminished activity of the enzyme, dramatically increasing the risk for esophageal cancer. This study was designed to evaluate the ALDH2 gene polymorphism as a predictor of the development of cancers prevalent in Japanese alcoholics. We performed ALDH2 genotyping on lymphocyte DNA samples from Japanese alcoholic men (487 cancer-free; 237 with cancer, including 34 oropharyngolaryngeal, 87 esophageal, 58 stomach, 46 colon, 18 liver, 7 lung, 9 other sites, and 19 multiple primary cancers in two or three organs). The frequencies of the mutant ALDH2*2 allele were significantly higher in alcoholics with oropharyngolaryngeal (52.9%), esophageal (52.9%), stomach (22.4%), colon (21.7%) and esophageal cancer concomitant with oropharyngolaryngeal and/or stomach cancer (78.6%), than in cancer-free alcoholics (9.0%). After adjustment for age, daily alcohol consumption and amount of cigarette smoking, significantly increased risks (odds ratios) in the presence of the ALDH2 *2 allele were found for oropharyngolaryngeal (11.14), esophageal (12.50), stomach (3.49), colon (3.35), lung (8.20) and esophageal cancer concomitant with oropharyngolaryngeal and/or stomach cancer (54.20) but not for liver or other cancers. These results suggest a general role of acetaldehyde, a recognized animal carcinogen, in the development of human cancers.

[Comparative effect of tranexamic acid on the reduction of bleeding during and after cardiac surgery]

The administration of tranexamic acid (TA), an antifibrinolytic agent, prior to cardiopulmonary bypass (CPB) has been reported to reduce bleeding after cardiac surgery. In a retrospective clinical trial, 99 adults patients undergoing open heart surgery received TA (CABG, TA (+): n = 20; Valve replacement, TA (+): n = 20) or did not receive TA (CABG, TA (-): n = 20: Valve replacement, TA (-): n = 19). In the TA group, just after induction of general anesthesia, a 160 mg.kg-1 dose of TA was administered intravenously. In each group, bleeding volumes during operation, and at 6 and 24 hours after operation, were compared. Patients of [CABG, TA (+)] group had significantly less intraoperative and total blood loss [total blood loss 608 g : 313 g, intraoperatively, 134 g at 6 hours, and 296 g at 24 hours] compared with [CABG, TA (-)] group (total blood loss 1043 g: 640 g, intraoperatively, 232 g at 6 hours, and 403 g at 24 hours). Additionally, in patients of Valve replacement, TA (+) group had less but not significant total blood loss (total blood loss 903 g: 523 g, intraoperatively, 173 g at 6 hours, and 380 g at 24 hours) compared with TA (-) group (total blood loss 1237 g: 863 g, intraoperatively, 214 g at 6 hours, and 374 g at 24 hours). TA administered prior to CPB may reduce the amount of bleeding during and after cardiac surgery.

Short-term follow-up after endoscopic mucosectomy of early esophageal cancer and aldehyde dehydrogenase-2 genotype in Japanese alcoholics

The risk of the future development of primary esophageal cancer after endoscopic esophageal mucosal resection of esophageal cancer is not known; hence, there are no established guidelines for follow-up surveillance programs. Simultaneous occurrence of multiple cancers associated with esophageal cancer is common among heavy drinkers who have the inactive form of aldehyde dehydrogenase-2 (ALDH2) as a risk factor. Thirty-four Japanese male alcoholics with intraepithelial or mucosal squamous cell carcinoma in the esophagus were treated by endoscopic esophageal mucosal resection, followed by endoscopy and esophageal iodine staining, to find the additional development of primary esophageal cancer. Primary esophageal squamous cell carcinoma was detected in nine patients (26.5%) at 3-21 months after the first cancer diagnosis. Cancer occurred more frequently in patients with inactive ALDH2 than it did in those with active ALDH2 [42.1% (8 of 19) versus 6.7% (1 of 15), P = 0.047], and it occurred more frequently in those with multiple esophageal cancers than it did in those without them [60.0% (6 of 10) versus 12.5% (3 of 24), P = 0.009]. Kaplan-Meier estimates of the proportions of patients with additional primary esophageal cancers showed that patients with inactive ALDH2 (P = 0.024) or multiple esophageal cancers (P = 0.007) had a significantly increased likelihood of the development of additional cancer. Close follow-up examinations using endoscopy and iodine staining are needed for such high-risk patients.

Staphylococcus aureus causing chorioamnionitis and fetal death with intact membranes at term. A case report

BACKGROUND

Neonatal infection without premature rupture of amniotic membranes occurs in 1-2% of births. The prevalence of membrane inflammation among term births is approximately 10%. There has been only one case report of Staphylococcus aureus as the cause of chorioamnionitis with intact membranes.

CASE

A 24-year-old woman was admitted at 38 weeks of pregnancy with labor pains. On admission, she had a slight fever of 37.8 degrees C, but the other physical findings were within normal limits. There were no symptoms or signs of membrane rupture. Fetal heart monitoring showed slight tachycardia, 160 beats per minute, and loss of variability. Fetal death was detected when the fetal monitoring was resumed after being interrupted for 30 minutes. A male infant weighing 2,920 g was born dead. Artificial rupture of the membranes had been performed just before delivery.

CONCLUSION

Culture specimens from the placenta and cord blood showed growth of S aureus, and histologic examination revealed chorioamnionitis. The bacteriologic evidence from the infant clearly identified S aureus.

Huge solitary osteochondroma at T11 level causing myelopathy: case report

A solitary osteochondroma of the vertebral column is rare, and also it will rarely cause neurological deficits. Myelopathy from a tumour usually presents insidiously with neurological deficits. We report a case of a huge solitary osteochondroma at T11 level with an acute onset of myelopathy induced by a minor trauma. MRI findings of a spinal osteochondroma has rarely been described. In our patient, the MRI demonstrated an outer osteochondral layer and an ossified centre of the mass. A literature review has also been undertaken.

Efficiency of recombination by Cre transient expression in embryonic stem cells: comparison of various promoters

The Cre-loxP recombination system of bacteriophage P1 is frequently utilized in genetic manipulation in embryonic stem (ES) cells. The level of Cre expression is critical to induce loxP site-specific recombination in ES cells. To compare the efficiency of recombination, we constructed four Cre expression vectors driven by different promoters: cytomegarovirus/chicken beta-actin (CAG) promoter, human polypeptide chain elongation factor 1alpha (hEF-1alpha) promoter, mouse phosphoglycerate kinase-1 (mPGK) promoter, and polyoma enhancer/herpes simplex virus thymidine kinase (MC1) promoter. We introduced these Cre expression vectors by electroporation into three ES cell lines carrying a single copy of CAG-loxP-chloramphenicol acetyltransferase (CAT) gene-loxP-beta-galactosidase (beta-gal) gene construct. Since the Cre-mediated recombination leads to excision of the CAT gene, the efficiency of recombination can be monitored as beta-gal expression. No selection system was used in the experiments. The maximum recombination frequency was obtained when the CAG promoter was used, followed by the hEF-1alpha promoter, the mPGK promoter and the MC1 promoter in order. These results indicate that the efficiency of recombination in transient expression system correlates with the promoter activity of Cre expression vector. Thus, it is important to choose the promoter for effective recombination by Cre.

[Histopathological examinations of dural arteriovenous malformations of posterior fossa]

Two cases of dural arteriovenous malformation (DAVM) of the posterior fossa were presented and a histopathological examination was described. After embolization of the feeding arteries, DAVMs of the posterior fossa were removed with the adjacent sinus. Serial sections of the surgical specimens showed an abnormal mass with dilated, tortuous vessels of varying diameters in the sinus wall, and partially hyalinized connective tissue around the vessels. The elastic lamina of the sinus wall was interrupted and a mass of abnormal vessels developed into the subintimal layer of the sinus. Fistulas, about 200 microns in diameter, were formed between arterialized dural veins and dural arteries which had obvious internal elastic lamina. An opening of the fistula of the abnormal vessel, 25 microns in diameter, to the sinus lumen was also seen. No stage of organized thrombus could be seen in the sinus lumen. These findings strongly suggested that physiologically existing arteriovenous fistulas within the dura mater, which have been reported by Kerber et al, had developed due to many factors which increase intracranial pressure. They protruded into the sinus lumen in such a way that it could cause stenosis or obstruction of the sinus. In conclusion it can be said that an obstructive lesion of dural sinus is considered of itself to be DAVM in most cases and sinus thrombosis is the result of the DAVM.

Cloning and expression of purine nucleoside phosphorylase I gene from Bacillus stearothermophilus TH 6-2

Bacillus stearothermophilus TH 6-2 has two kinds of purine nucleoside phosphorylases (Pu-NPase I and Pu-NPase II). The Pu-NPase I is a functional homolog of eukaryotic purine nucleoside phosphorylases that can catalyze the phosphorolysis of inosine and guanosine, but not adenosine, the primary substrate of Pu-NPase II. The Pu-NPase I gene of TH 6-2 has been cloned, sequenced, and expressed in E. coli. The gene corresponded to an open reading frame of 822 nucleotides that translates into a putative 274-amino acid protein with a molecular weight of 29,637. The deduced amino terminus sequence completely coincided with that found for the purified enzyme. The cloned gene was overexpressed in E. coli by using the trc promoter to produce an active enzyme in large quantities. The amino acid sequence of Pu-NPase I shared 50% similarity with those of human and mouse purine nucleoside phosphorylases.

Thoracolumbar burst fracture with horizontal fracture of the posterior column

STUDY DESIGN

Nine patients with thoracolumbar burst fractures associated with horizontal fractures in the posterior column were studied retrospectively.

OBJECTIVES

To clarify the clinical and radiographic findings and evaluate the postoperative results for this type of fracture.

SUMMARY OF BACKGROUND DATA

It is not well recognized that burst fractures occasionally are accompanied by horizontal fractures of the posterior column such as those that result from seatbelt-type injuries. This type of burst fracture differs from flexion-distraction injuries combined with burst fracture, which are accompanied by horizontal fractures not only in the posterior but also in the middle column. Radiographic features of these two different types of injuries are very similar to each other, and their differentiation in diagnosis and treatment has not been recognized clearly.

METHODS

Patients were reviewed using a combination of clinical records, follow-up examination, and radiographic data (computed tomography [CT], plain radiographs, and tomographs). Anterior spinal fusion was performed in eight patients using the Kaneda device (Mizuhoika Tokyo, Japan), and one was treated by posterior fusion with pedicle screw fixation. The average follow-up period was 4 years.

RESULTS

Patients with fractures of this type represented 21% of the 48 patients with thoracolumbar burst fractures. The injury was sustained by falling in all nine patients. All of the burst fractures were Denis' type B. The horizontal fracture was located at the lamina and spinous process in the posterior column of the upper vertebra adjacent to the involved vertebra in all nine patients. The integrity of the ligamentous structures of the middle column, such as the posterior longitudinal ligament, the periosteum, and the outermost anulus, was confirmed at surgery in eight patients, although not in the patient who underwent posterior fusion. One patient required surgery because of progression of kyphotic deformity during conservative treatment. Solid fusion with no complications was noted in all patients.

CONCLUSION

This type of burst fracture is not accompanied by ligamentous injuries because of distraction force in the middle column, which is not present in flexion-distraction injuries, but it seems to be more unstable than burst fractures with no horizontal splitting of the posterior column and requires surgical stabilization.

Outcome of non-immune hydrops fetalis and a fetus with hydrothorax and/or ascites: with some trials of intrauterine treatment

The subject of this study was 38 cases of non-immune hydrops fetalis and 11 cases of fetal hydrothorax and/ or ascites (FH/A), a syndrome characterized by the accumulation of pleural effusion and/or ascitic fluid, without generalized skin edema, due to various etiologies, admitted to the obstetrics ward of Hokkaido University Hospital during the period between 1987 and 1994. Fetal treatment consisted of (1) intravascular transfusion or intra-abdominal transfusion for anemia, (2) frequent centesis or shunt insertion for pleural effusion and ascites, (3) reduction of cystic hygroma by puncturing and OK432 injection, and (4) intravascular or maternal injection with an anti-arrhythmic drugs to treat tachycardia. The outcome of NIHF and FH/A was assessed to be able to make a prognosis in NIHF and to compare the efficacy of fetal therapy in cases with (15 cases: 9 NIHF, 6 FH/A) and without (34 cases: 29 NIHF, 5 HF/A) intrauterine treatment. The average survival rates were 23.1% in NIHF and 54.5% in FH/A. None of fetuses with a chromosomal abnormality or cystic hygroma survived. The average GW at the time of detection of NIHF by ultrasonography was week 24.9 +/- 1.1 (mean +/- S.E., n = 38). The average GW at the time of detection of FH/A by ultrasonography was week 26.6 +/- 1.8 (n = 11). NIHF was detected significantly earlier in the IUFD and early neonatal death group (GW 22.4 +/- 1.4) than in the survivor group (GW 27.6 +/- 1.2) (p < 0.05). FH/A was also detected earlier in the IUFD/early neonatal death group than in the survivor group (GW 21.8 +/- 2.4 vs. 31.1 +/- 1.1, n = 11, p < 0.05). The survival rate in the intrauterine treatment group was higher than in the nontreatment group (treatment group: 10/15; non-treatment group: 5/34, p < 0.001). After the trial of intrauterine treatment in the 15 cases mentioned above, some efficacy was observed in 7 cases (reduction of cysts, effusion or edema, disappearance of arrhythmia).

A case of intrauterine medical treatment for cystic hygroma

We report the first case of an intrauterine treatment for cystic hygroma. Guided by ultrasonography, we first removed intracystic fluid from two cysts and then injected OK-432 into each fetal cyst at 21 and 28 weeks of gestation. No re-enlargement of the cysts was subsequently observed. At 38 weeks of gestation, a male infant was delivered transvaginally. Only a slight skin fold was observed in the nuchal area of the neonate, indicating the effectiveness of OK-432 for the intrauterine treatment of cystic hygroma.

Genotypes of alcohol-metabolizing enzymes and the risk for alcoholic chronic pancreatitis in Japanese alcoholics

Genetic predisposition to alcoholism and alcoholic liver disease has been reported. However, genetic susceptibility to alcoholic pancreatitis is still a matter of debate. To determine it, we examined genotype patterns of aldehyde dehydrogenase (ALDH2), alcohol dehydrogenase (ADH2 and ADH3), and cytochrome P-4502E1 (CYP2E1) in alcoholic pancreatitis patients. In 296 alcoholic patients, 52 cases showed findings of chronic pancreatitis by ultrasonography and x-ray computed tomography and/or had a history of pancreatitis (P+). The remaining 244 patients had neither abnormal findings of the image examinations nor a history of pancreatitis (P-). As for the ADH2 genotype, distribution of 2(1)/2(1), 2(1)/2(2), and 2(2)/2(2) was 22, 37, and 42% in P+ patients, whereas 34, 35, and 30% in P- patients, respectively. The frequency of ADH2(2)/2(2) genotype was significantly higher in P+ patients, compared with that in P- patients. There were no significant differences in the distribution of ADH3, ALDH2, and CYP2E1 genotypes between P+ and P- patients. In 14 alcoholic patients who showed low contents of fecal chymotrypsin, which suggests dysfunction of pancreatic exocrine, the rate of ADH2(2)/2(2) genotype also tended to be higher (50%) than in 74 controls who showed normal contents of the fecal chymotrypsin (28%). No differences were observed in genotypes of ADH3, ALDH2, and CYP2E1. Moreover, the frequency of ADH2(2)/2(2) genotype was significantly higher in autopsy cases with interlobular fibrosis in the pancreas, which suggests alcoholic pancreatic damage, than in cases with only intralobular pancreatic fibrosis. These data suggest that the risk of alcoholic pancreatitis seems to be associated with the presence of ADH2(2)/2(2) genotype.

Reduced messenger RNA expression level of p21 CIP1 in human colorectal carcinoma tissues and its association with p53 gene mutation

p21 Cip1 was first isolated as one of the cyclin-dependent kinase (Cdk) interacting proteins induced by wild-type p53 gene product, and it appears to play an essential regulatory role in the control of cell proliferation as a potent, tight-binding inhibitor of cyclin-Cdk complex that blocks the G1/S transition of the cell cycle. We have now examined the p21 Cip1 mRNA expression levels in 16 surgically excised human colorectal tumor and non-tumor tissues by Northern-blot analysis with reference to the identification of p53 gene mutations. p53 gene mutations were detected in 6 tumor tissues but not in the other 10 tissues by the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) method and following direct sequencing. The mean p21 Cip1 mRNA expression level in tumor tissues was significantly suppressed compared to that of non-tumor tissues, irrespective of p53 gene mutations. In p53 gene mutation-detected cases, the mean expression level of p21 Cip1 mRNAs of tumor tissues was about 60% of that of cases without p53 gene mutation. Moreover, the relative mRNA expression levels of p21 Cip1 significantly decreased as the pathohistological stages progressed by Dukes' staging system, while in patients with liver metastasis these levels were significantly suppressed compared to those of patients without organ metastasis. These results indicate that reduced expression of p21 Cip1 mRNA is critical for growth activity and malignant potential of human colorectal carcinoma, and that the decrease in p21 Cip1 mRNA level is due to p53 gene mutation as well as other mechanisms during human colorectal carcinogenesis.

Molecular cloning and expression of the pyrimidine nucleoside phosphorylase gene from Bacillus stearothermophilus TH 6-2

The pyrimidine nucleoside phosphorylase (Py-NPase) of Bacillus stearothermophilus TH 6-2 is a dimer of 46-kDa subunits and catalyzes the reversible phosphorolysis of uridine and thymidine. The gene encoding this pyrimidine nucleoside phosphorylase (pyn gene) has been cloned and sequenced from B. stearothermophilus TH 6-2. The pyn gene corresponded to an open reading frame of 1299 nucleotides that translates into a putative 433 amino acid protein with a molecular weight of 46,271. The deduced amino terminal sequence of Py-NPase coincided with that previously found for the purified enzyme. The deduced amino acid sequence of Py-NPase shared significant similarity with those of human and Escherichia coli thymidine phosphorylases. The cloned pyn gene was overexpressed in E. coli cells to produce an active enzyme in large quantities that accounted for approximately 20% of the total protein.

Reduced messenger RNA expression level of p21 CIP1 in human colorectal carcinoma tissues and its association with p53 gene mutation

p21 Cip1 was first isolated as one of the cyclin-dependent kinase (Cdk) interacting proteins induced by wild-type p53 gene product, and it appears to play an essential regulatory role in the control of cell proliferation as a potent, tight-binding inhibitor of cyclin-Cdk complex that blocks the G1/S transition of the cell cycle. We have now examined the p21 Cip1 mRNA expression levels in 16 surgically excised human colorectal tumor and non-tumor tissues by Northern-blot analysis with reference to the identification of p53 gene mutations. p53 gene mutations were detected in 6 tumor tissues but not in the other 10 tissues by the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) method and following direct sequencing. The mean p21 Cip1 mRNA expression level in tumor tissues was significantly suppressed compared to that of non-tumor tissues, irrespective of p53 gene mutations. In p53 gene mutation-detected cases, the mean expression level of p21 Cip1 mRNAs of tumor tissues was about 60% of that of cases without p53 gene mutation. Moreover, the relative mRNA expression levels of p21 Cip1 significantly decreased as the pathohistological stages progressed by Dukes' staging system, while in patients with liver metastasis these levels were significantly suppressed compared to those of patients without organ metastasis. These results indicate that reduced expression of p21 Cip1 mRNA is critical for growth activity and malignant potential of human colorectal carcinoma, and that the decrease in p21 Cip1 mRNA level is due to p53 gene mutation as well as other mechanisms during human colorectal carcinogenesis.

Evaluation of bone density in newborn infants by computed x-ray densitometry

We evaluated bone density in term and preterm infants using computed x-ray densitometry, which permits measurement of bone density with minimal disturbance to the infants in their incubators. Bone density, bone width, and bone length of the right radius were determined in 155 infants of appropriate weights for their gestational ages (23 to 41 weeks). A curve for intrauterine bone growth was extrapolated from these data. The mean coefficients of variations for variabilities for intra- and interobserver error for all measurements were < 3.5%. In 18 infants, measurements of the right forearm were obtained in two positions to confirm the validity of densitometric measurements. The mean coefficients of variation were 3.42% for bone density, 3.48% for bone width, and 0.21% for bone length. Bone density was significantly correlated with gestational age (r = 0.924) and birth weight (r = 0.921). Bone width and length were also correlated with gestational age (r = 0.866 and 0.937) and birth weight (r = 0.878 and 0.954). Our results suggest that computed x-ray densitometry is a useful method for evaluation of bone density in preterm infants, including those in an intensive care environment.