[An analysis on prognostic significance of histopathologic risk factor in uterine endometrial carcinoma]

Prognostic risk factors in histopathologic findings were analyzed in the data for one hundred and thirteen patients with uterine endometrial carcinoma who were treated surgically. Univariate survival analysis with Kaplan-Meier methods revealed that the nuclear grade (p less than 0.005), lymph-vascular space invasion (p less than 0.005), histologic grade (p less than 0.01) and histologic type (p less than 0.01) correlated with the patient's prognosis. Among surgical FIGO stages II and III, there was similar significance in the correlations in the nuclear grade (p less than 0.05), lymph-vascular space invasion (p less than 0.0001) and histologic type (p less than 0.05), although there was difference (p less than 0.05) only between grade 1 and grade 3 in the histologic grade. Multivariate survival analysis with a proportional hazard regression model showed that the nuclear grade (p less than 0.005) and lymph-vascular space invasion (p less than 0.01) correlated significantly with the prognosis. The hazard ratios with a 95% confidence interval for each of these factors were 19.2 (3.2-115.7) and 16.9 (2.1-135.3), respectively. The 3-year survival rate was 98% for a hazard ratio less than 64.7, and 45% for one more than 67.4, between which there was a significant difference (p less than 0.0001). And univariate survival analysis of this hazard ratio also revealed strong correlations with the patient's prognosis. These results suggest that it is of great importance to adopt the hazard model including such factors as the nuclear grade and lymph-vascular space invasion in estimating the patient's prognosis and proceeding to adequate post-operative therapy for individual patient.

Re-transformation of non-transformed hybrids between c-myc-activating mouse plasmacytoma cells and normal fibroblasts by transfection with activated c-Ha-ras but not c-myc

In a mouse plasmacytoma S194, c-myc oncogene is rearranged with Ig gene by chromosomal translocation and is consequently activated. We previously reported that transformation of phenotype and expression of rearranged c-myc were repressed in independently isolated hybrid clones, I-1 and IV-10, between S194 and normal fibroblasts. In order to investigate the relationship between transformation of phenotype and oncogene expression, transcriptionally enhanced c-myc or activated c-Ha-ras was transfected into I-1 or IV-10I, a subclone of IV-10. Transfectants expressing high levels of c-myc were found to retain the non-transformed phenotypes. On the other hand, transfectants expressing activated c-Ha-ras showed the transformed phenotypes. These results suggest that enhanced expression of c-myc is not sufficient for re-transformation of the non-transformed hybrid clones between c-myc-activating plasmacytoma cells and normal fibroblasts, but expression of activated c-Ha-ras could diminish or overcome the tumor-suppressive activity of normal fibroblasts.

Effects of sodium butyrate on the rearranged c-myc expression in mouse plasmacytoma cells

The expression of c-myc mRNA was examined after 4 h of sodium butyrate treatment in a mouse plasmacytoma (MPC) cell line (S194). Steady-state levels of rearranged c-myc mRNA were suppressed by the agent in S194 cells. Run-on assay demonstrated that the suppression of the rearranged c-myc mRNA in the MPC was correlated with the transcriptional downregulation of the gene. The suppression was also accompanied by the reduced DNase I sensitivity of the gene. These findings suggest that the rapid downregulation of c-myc mRNA by sodium butyrate is subject to regulation at the transcriptional level following the alteration of the DNase I sensitive chromatin structure in mouse plasmacytoma cells.

Extracorporeal spread and its prognostic impact in stages I and II (FIGO) endometrial carcinoma

Prognostic risk factors were statistically analyzed from the histopathologic data obtained from 90 Japanese women with stages I and II endometrial carcinoma treated surgically, including systemic retroperitoneal lymph node dissection, between June 1979 and June 1989. In stage Ia endometrial carcinoma, pelvic and paraaortic nodes metastasis were seen in 13.8(4/29)% and 0.0(0/19)% of patients, respectively. In stage Ib, the incidence of pelvic and paraaortic node metastasis was 25.6(11/43)% and 9.7(3/31)%, respectively. In stage II, the incidence was 38.9(7/18)% and 13.3(2/15)%, respectively. Prognosis of patients even with deep myometrial invasion (greater than or equal to 2/3) or G3 tumor was fairly good (5-year survival rate: 87.5% and 85.7%, respectively) if the disease was histologically confined to the uterine corpus. Once the tumor spread outside the corpus uteri, the survival rate of patients was strongly affected by the grade of the tumor, moderate to marked lymph-vascular space invasion of tumor cells, or tumor invading middle or outer third of myometrium (P less than 0.05 for each factor). In summary, endometrial cancer frequently metastasize to pelvic and paraaortic lymph nodes even in the early stages, and lymph node metastasis and other extracorporeal spread of disease have a serious impact on patient survival. Prognosis of patients with extracorporeal spread of disease seems to be determined by the high grade of tumor and lymph-vascular space invasion. These results suggest that surgical exploration including paraaortic lymph node dissection to accurately evaluate the extent of the disease is essential to estimate the patient's prognostic risk and to individualize the treatment schedule.

The length polymorphism in the 5' flanking region of the human beta-globin gene with denaturing gradient gel electrophoresis in a Japanese population

The ATTTT repeat polymorphism located approximately 1,400 base pairs (bp) upstream from the beta-globin structural gene was analyzed by denaturing gradient gel electrophoresis (DGGE) of RNA:DNA duplexes. A study of 81 unrelated Japanese from Hiroshima revealed a sequence heteromorphism in this site. The alleles with five and six repeats of the ATTTT unit, which have been reported, were found in polymorphic proportions. Two unreported alleles were also detected, the first, in two persons, characterized by seven repeats and the other, in a single person, having an A-to-G nucleotide substitution in the fifth repeat.

Chromosome translocation and c-MYC activation by Epstein-Barr virus and Euphorbia tirucalli in B lymphocytes

Dual exposure to Epstein-Barr virus and purified 4-deoxyphorbol ester derived from the plant Euphorbia tirucalli induced a high frequency of chromosomal rearrangements in human B lymphocytes in vitro. Rearrangements most commonly affected chromosome 8, the chromosome most often showing structural changes in Burkitt's lymphoma (BL) cells. E tirucalli is indigenous in parts of Africa where BL is endemic and may be an important risk factor for the disease.

[An analysis of prognostic significance of new FIGO staging (1989) of endometrial cancer]

Histopathologic factors were investigated in the data for ninety-one patients with endometrial carcinoma who were treated surgically. Each of these subjects was reclassified according to the new FIGO surgical criteria (1989) for stages and the relationship between the new classifications and the prognosis of patients was analyzed. One third of the patients (24/72) with clinical FIGO stage I (1983) had extracorporeal spread of the disease and these cases were reclassified as surgical stages II and III. Among clinical stage Ib patients there were many more with extracorporeal spread than among those in clinical stage Ia (p less than 0.005) although there was no difference between the histopathological characteristics (histologic grade, myometrial invasion, cervical involvement, adnexal involvement and pelvic lymph node metastasis) of the stage Ia and Ib groups. Univariate survival analysis revealed that the histologic grade (p less than 0.05), myometrial invasion (p less than 0.05), cervical involvement (p less than 0.005) and pelvic lymph node metastasis (p less than 0.005) correlated with the patient's prognosis. Multivariate survival analysis with the proportional hazard regression model showed that cervical involvement (p = 0.05) and the new stage classification (p = 0.03) correlated significantly with the prognosis. The cumulative 5-year survival rate by clinical stage (1983) was 87% for stage I (Ia: 96%, Ib: 80%) and 72% for stage II, between which no significant difference was determined. The survival rate for stage III was not calculated because there was only one case with stage III disease in this study.(ABSTRACT TRUNCATED AT 250 WORDS)

Detection of deletions, insertions and single nucleotide substitutions in cloned beta-globin genes and new polymorphic nucleotide substitutions in beta-globin genes in a Japanese population using ribonuclease cleavage at mismatches in RNA:DNA duplexes

The applicability of ribonuclease cleavage at mismatches in RNA:DNA duplexes (RNase cleavage method) for determining nucleotide variant rates has been examined in a Japanese population. DNA segments of various lengths obtained from 4 different regions of a normal and 3 thalassemic cloned human beta-globin genes were inserted into transcription vectors. Sense and antisense RNA probes uniformly labeled with 32P were prepared. When RNA probes of 771 nucleotides (nt) or less were hybridized with cloned DNAs and the resulting duplexes were treated with a mixture of RNases A and T1, the length of products agreed with theoretical values. Twelve possible mismatches were examined. Since both sense and antisense probes were used, uncleavable mismatches such as G:T and G:G which were made from one combination of RNA and DNA strands could be converted to the cleavable C:A and C:C mismatches, respectively, by using the opposite combination. Deletions and insertions of 1 (G), 4 (TTCT), 5 (ATTTT) and 10 (ATTTTATTTT) nt were easily detected. A polymorphic substitution of T to C at position 666 of the second intervening sequence (IVS2-666) of the beta-globin gene was detected using genomic DNAs from cell lines established from the peripheral B lymphocytes of 59 unrelated Japanese from Hiroshima or those amplified by polymerase chain reaction (PCR). The frequency of the gene with C at the IVS2-666 (allele C) was 0.48 and that of the gene with T (allele T) was 0.52. The associations of the 2 alleles were in agreement with Hardy-Weinberg proportions. No contradiction to Mendelian inheritance was observed in the results obtained from 11 family studies. Two new polymorphic substitutions of C to A and A to T were detected at nucleotide positions 1789 and 1945 from the capping site, respectively, using genomic DNAs amplified by PCR. The feasibility of the RNase cleavage method combined with PCR for large-scale screening of variation in chromosomal DNA is discussed.

The children of parents exposed to atomic bombs: estimates of the genetic doubling dose of radiation for humans

The data collected in Hiroshima and Nagasaki during the past 40 years on the children of survivors of the atomic bombings and on the children of a suitable control population are analyzed on the basis of the newly revised estimates of radiation doses. No statistically significant effects emerge with respect to eight different indicators. Since, however, it may confidently be assumed some mutations were induced, we have taken the data at face value and calculated the minimal gametic doubling doses of acute radiation for the individual indicators at various probability levels. An effort has also been made to calculate the most probable doubling dose for the indicators combined. The latter value is between 1.7 and 2.2 Sv. It is suggested the appropriate figure for chronic radiation would be between 3.4 and 4.5 Sv. These estimates suggest humans are less sensitive to the genetic effects of radiation than has been assumed on the basis of past extrapolations from experiments with mice.

An improved method for the detection of genetic variations in DNA with denaturing gradient gel electrophoresis

We have examined the feasibility of denaturing gradient gel electrophoresis (DGGE) of RNA:DNA duplexes to detect variations in genomic and cloned DNAs. The result has demonstrated that employment of RNA:DNA duplexes makes DGGE much more practical for screening a large number of samples than that of DNA:DNA heteroduplexes originally developed by Lerman et al. (1986), because preparation of RNA probes is easier than that of DNA probes. Three different 32P-labeled RNA probes were produced. Genomic or cloned DNAs were digested with restriction enzymes and hybridized to labeled RNA probes, and resulting RNA:DNA duplexes were examined by DGGE. The presence of mismatch(es) was detected as a difference in mobility of bands on the gel. The experimental conditions were determined using DNA segments from cloned normal and 3 thalassemic human beta-globin genes. The results of the experiments on the cloned DNAs suggest that DGGE of RNA:DNA duplexes will detect nucleotide substitutions and deletions in DNA. In the course of these studies, a polymorphism due to a single-base substitution at position 666 of IVS2 (IVS2-666) of the human beta-globin gene was directly identified using genomic DNA samples. A study of 59 unrelated Japanese from Hiroshima was made in which the frequency of the allele with C at IVS2-666 was 0.48 and that of the allele with T was 0.52. This approach was found to be very effective for the detection of heritable variation and should be a powerful tool for the detection of fresh mutations in DNA, which occur outside the known restriction sites.

Transcriptional down-regulation of the rearranged C-myc expression in murine cell hybrids between a plasmacytoma and a T-cell lymphoma

Regulation of the rearranged and non-rearranged c-myc expression was studied in murine cell hybrids (SBWI and SBWII) between plasmacytoma (S194) and T-cell lymphoma (BW5147) cells. Expression of the rearranged c-myc of heterogeneous mRNA sizes (1.8 approximately 2.4 kb) was markedly down-regulated in these hybrids regardless of retention of the gene. On the other hand, expression of the non-rearranged c-myc (2.4 kb) was not significantly affected in these hybrids. Treatment of SBWI hybrid cells with cycloheximide enhanced the non-rearranged c-myc 2- to 4-fold but did not release the down-regulation of the rearranged c-myc at all, suggesting that the down-regulation of the rearranged c-myc in the hybrid cells was mainly at a transcriptional rather than a post-transcriptional level. This was supported by the results of nuclear run-on assay: the high level of run-on transcripts in S194 cells declined in SBWI hybrid cells comparable to the level in BW5147 cells. The rearranged c-myc was hemi-methylated in S194 cells and the pattern was the same in SBWI hybrid cells. Furthermore, down-regulation of the rearranged c-myc in the hybrid was also not restored by treatment with 5-azacytidine (5-AzaC), 12-O-tetradecanoylphorbol-13-acetate (TPA) or forskolin, suggesting no causative involvement of DNA methylation or protein phosphorylation in down-regulation. Higher DNase I sensitivity of the rearranged c-myc in S194 cells decreased to a similar extent to that of the non-rearranged c-myc after cell fusion with BW5147 cells. These results suggest that expression of the rearranged c-myc is down-regulated at the level of transcription in murine cell hybrids between a plasmacytoma and a T-cell lymphoma, probably by changing chromatin configuration around the gene from the open to the closed state.

[The incidence and clinical significance of paraaortic lymph node metastases in patients with uterine cervical cancer]

Paraaortic lymph node dissection was performed in the treatment of patients with carcinoma of the cervix who were subjected to radical hysterectomy between June, 1982 and March, 1988 at the Department of Obstetrics and Gynecology, Hokkaido University Hospital, Sapporo, Japan. Thirteen out of 246 (5.3%) patients had metastases in the paraaortic lymph node. Of the patients with stage I carcinoma of the cervix, 1.0 per cent had positive paraaortic lymph node. Of the patients with stage II carcinoma, 4.9 per cent had metastases in the paraaortic lymph nodes, and of the stage III patients, 16.7 per cent had positive paraaortic lymph nodes. The incidence of paraaortic node involvement increased along with the advance of the disease. Of the patients with squamous cell carcinoma of the cervix, 4.6 per cent had paraaortic lymph node metastases. Of the patients with adenocarcinoma of the cervix including mixed carcinoma, 6.8 per cent had positive paraaortic node. All the patients with positive paraaortic lymph nodes had metastatic diseases in the pelvic nodes. In addition, the number of groups of positive pelvic nodes in the patients with positive paraaortic lymph nodes was significantly larger than that in those with negative paraaortic nodes. At the time of reporting, seven out of 13 patients with positive paraaortic lymph node have died of the disease. The mean survival period of those seven patients was 14.9 +/- 12.2 (mean +/- SD) months. Of the remaining six surviving patients, three have been doing well for more than three years.(ABSTRACT TRUNCATED AT 250 WORDS)

Point substitutions in Japanese alloalbumins

We have completed the structural study of five rare types of inherited albumin variants (alloalbumins) discovered in the Biochemical Genetics Study of 15,581 unrelated children in Hiroshima and Nagasaki. We have also identified the structural change in five other alloalbumin specimens detected during clinical electrophoresis of sera from Japanese living near Tokyo. Each of the five albumin variants from Nagasaki and Hiroshima has a single amino acid substitution. All of these substitutions differ, and none has been reported in non-Japanese populations. No instances of proalbumin variants or of albumin B (the most frequent alloalbumins in Caucasians) were detected in the children in Hiroshima and Nagasaki. However, one instance of a variant proalbumin and two examples of albumin B occurred in Japanese from the vicinity of Tokyo. In addition a previously unreported point substitution was found in albumin Tochigi, which is present in two unrelated persons from Tochigi prefecture. Four of the point mutations in the Japanese alloalbumins are in close proximity in a short segment of the polypeptide chain (residues 354-382) in which three additional point substitutions have been reported in diverse populations. These results, combined with earlier data, suggest that point substitutions are grouped in certain segments of the albumin molecule.

Reduced DNase I sensitivity of the rearranged c-myc gene in somatic cell hybrids between murine plasmacytoma cells and fibroblasts

In mouse plasmacytoma (MPC) S194, the rearranged c-myc gene was much more sensitive to DNase I digestion than the nonrearranged gene. The sensitivity of the rearranged c-myc was markedly reduced to the same extent as that of the nonrearranged one in hybrids between the MPC cells and the fibroblasts, but not in a hybrid between the MPC and the spleen cells. These results suggest that trans-acting factors in fibroblasts alter the DNase I-sensitive structure of the rearranged c-myc gene.

Implications of the Hiroshima-Nagasaki genetic studies for the estimation of the human "doubling dose" of radiation

Since 1946 a continuous effort to evaluate the potential genetic effects of the atomic bombs has been sustained. Observations on children born in Hiroshima and Nagasaki include sex ratio, congenital malformations, stillbirths, survival of liveborn infants, chromosomal abnormalities (sex chromosomal abnormalities and balanced chromosomal rearrangements), mutations altering protein structure or activity, and physical growth and development. There are no statistically significant differences between the children of parents who received increased amounts of radiation at the time of the bombings and those whose parents did not. However, the difference between the two sets of children is consistent with the hypothesis of a genetic effect of the exposure, but its magnitude suggests humans are not as sensitive to the genetic effects of radiation as projected from the mouse paradigm.

Protein variants in Hiroshima and Nagasaki: tales of two cities

The results of 1,465,423 allele product determinations based on blood samples from Hiroshima and Nagasaki, involving 30 different proteins representing 32 different gene products, are analyzed in a variety of ways, with the following conclusions: (1) Sibships and their parents are included in the sample. Our analysis reveals that statistical procedures designed to reduce the sample to equivalent independent genomes do not in population comparisons compensate for the familial cluster effect of rare variants. Accordingly, the data set was reduced to one representative of each sibship (937,427 allele products). (2) Both chi 2-type contrasts and a genetic distance measure (delta) reveal that rare variants (P less than .01) are collectively as effective as polymorphisms in establishing genetic differences between the two cities. (3) We suggest that rare variants that individually exhibit significant intercity differences are probably the legacy of tribal private polymorphisms that occurred during prehistoric times. (4) Despite the great differences in the known histories of the two cities, both the overall frequency of rare variants and the number of different rare variants are essentially identical in the two cities. (5) The well-known differences in locus variability are confirmed, now after adjustment for sample size differences for the various locus products; in this large series we failed to detect variants at only three of 29 loci for which sample size exceeded 23,000. (6) The number of alleles identified per locus correlates positively with subunit molecular weight. (7) Loci supporting genetic polymorphisms are characterized by more rare variants than are loci at which polymorphisms were not encountered. (8) Loci whose products do not appear to be essential for health support more variants than do loci the absence of whose product is detrimental to health. (9) There is a striking excess of rare variants over the expectation under the neutral mutation/drift/equilibrium theory. We suggest that this finding is primarily due to the relatively recent (in genetic time) agglomeration of previously separated tribal populations; efforts to test for agreement with the expectations of this theory by using data from modern cosmopolitan populations are exercises in futility. (10) All of these findings should characterize DNA variants in exons as more data become available, since the finding are the protein expression of such variants.

Search for mutations altering protein charge and/or function in children of atomic bomb survivors: final report

A sample of (1) children whose parents had been proximally exposed (i.e., less than 2,000 m from the hypocenter) at the time of the atomic bombings of Hiroshima and Nagasaki and (2) a suitable comparison group have been examined for the occurrence of mutations altering the electrophoretic mobility or activity of a series of 30 proteins. The examination of the equivalent of 667,404 locus products in the children of proximally exposed persons yielded three mutations altering electrophoretic mobility; the corresponding figure for the comparison group was three mutations in 466,881 tests. The examination of a subset of 60,529 locus products for loss of enzyme activity in the children of proximally exposed persons yielded one mutation; no mutations were encountered in 61,741 determinations on the children of the comparison group. When these two series are compared, the mutation rate observed in the children of proximally exposed persons is thus 0.60 x 10(-5)/locus/generation, with 95% confidence intervals between 0.2 and 1.5 x 10(-5), and that in the comparison children is 0.64 x 10(-5)/locus/generation, with 95% intervals between 0.1 and 1.9 x 10(-5). The average conjoint gonad doses for the proximally exposed parents are estimated to be 0.437 Gy of gamma radiation and 0.002 Gy of neutron radiation. If a relative biological effectiveness of 20 is assigned to the neutron radiation, the combined total gonad dose for the parents becomes 0.477 Sv. (Organ absorbed doses are expressed in gray [1 Gy = 100 rad]; where dose is a mixture of gamma and neutron radiation, it is necessary because of the differing relative biological effectiveness of gamma and neutron radiation to express the combined gamma-neutron gonad exposures in sieverts [1 Sv = 100 rem]).

Diverse characteristics in potential waveform of His-Purkinje system--experimental and simulation studies

Reflection to the body surface of the single beat-potentials of the His-Purkinje system (HPS) was analysed by a single beat recording of the epicardial HPS potentials from the Langendorff perfused canine heart and by the reconstruction of HPS potentials on the basis of the cable concept. Unipolar epicardial HPS potentials from 8 leads distributed equidistantly over the basal region of the ventricles were amplified by a high gain (120 dB) amplifiers with an active bandpass filter (40-2400 kHz). The waveform of these HPS potentials differed in each lead. The largest (42 +/- 8 microV, mean +/- SE, n = 5) of these HPS potentials, which was obtained from the anterior free wall of the right ventricle, was composed of two peaks: the initial slow- and positive-peak and the late sharp- and negative-peak. The former peak appeared 12 +/- 3 msec (mean +/- SE, n = 5) ahead of the spike of the His-bundle electrogram (HBE) recorded from the close bipolar electrodes which were attached intracavitally along the membrane portion of the His-bundle. The latter appeared in coincidence with the spike of HBE. The extracellular potentials generated by HPS excitation were calculated by assuming that the excitation proceeds along the three dimensionally reconstructed HPS. The simulated waveform was in agreement with those of the epicardial HPS potentials. Thus, the HPS potentials on the body surface may inscribe a diverse waveform as a reflection of the complexed architecture of the whole HPS.

Heterozygosity and ethnic variation in Japanese platelet proteins

Sixty-two polypeptides visualized on silver-stained two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) preparations of platelets from 85 Japanese subjects, in total 5,252 spots, have been scored for genetic variation. Inherited variants of 11 of the polypeptides were recognized; the index of heterozygosity was 2.4% +/- 0.2%. Thus far, 10 genetic polymorphisms identified by 2-D PAGE of plasma, erythrocytes, or platelets have been identified in both Japanese and Caucasian subjects. A comparison of allele frequencies reveals four significant ethnic differences. We also observed four polypeptides exhibiting a low frequency polymorphism in one group but not in the other, as well as three polymorphisms in Caucasians for which no counterpart polypeptide has thus far been recognized in the Japanese group and, vice versa, 11 such polymorphisms in Japanese. Although a similar comparison of 7 enzyme polymorphisms studied with one-dimensional electrophoresis (1-D E) in the same populations revealed a relatively higher number of significant ethnic differences, evidence is presented that this is due primarily to the greater number of 1-D E observations entering into the calculation. It is argued that this similarity in the frequency of ethnic differences among the polypeptides studied by 2-D PAGE and by 1-D E is further evidence that the proteins revealed by 2-D PAGE do not differ greatly in their response to the interplay of mutation, selection, and drift from those revealed by 1-D E studies of plasma proteins and erythrocyte enzymes.

Amino acid substitutions in inherited albumin variants from Amerindian and Japanese populations

We report an effort to determine the basis for the altered migration of seven inherited albumin variants detected by one-dimensional electrophoresis in population surveys involving tribal Amerindians and Japanese children. An amino acid substitution has thus far been determined for four of the variants. The randomness in the albumin polypeptide of these and the other sixteen independently ascertained amino acid substitutions of albumin and proalbumin thus far established was analyzed; the clustering of eight of these at two positions in the six-amino acid propeptide sequence seems noteworthy. By comparison with other proteins studied by electrophoresis, albumin exhibits "average" variability. It is a paradox that individuals who, for genetic reasons, lack albumin exhibit no obvious ill effects; yet, electrophoretic variants of albumin are no more numerous than are variants of proteins, the absence of which results in severe disease.

Inherited electrophoretic variants detected in a Japanese population with two-dimensional gels of erythrocyte lysates

Genetic variation has been studied in erythrocyte lysates from 100 Japanese children and their parents by means of two-dimensional polyacrylamide gel electrophoresis. Fifty-five polypeptides selected without respect to variability were considered suitable for scoring. Genetic variation was encountered in 14 of these polypeptides. Family data show that the segregation of 13 variants is consistent with an autosomal codominant mode of inheritance; the remaining variant exhibits a sex-linked mode of inheritance. Of 8 presumably identical polypeptides found variable in Japanese and/or Caucasians, differences in the occurrence or allele frequencies of polymorphisms were recognized for four. Contrary to the experience of some investigators, the amount of variation and the ethnic differences we are encountering indicate that two-dimensional polyacrylamide gel electrophoresis is a sensitive tool for the study of genetic events.

Characterization of three electrophoretic variants of human erythrocyte triosephosphate isomerase found in Japanese

Three new electrophoretic variants of human erythrocyte triosephosphate isomerase (TPI) have been partially purified and compared with the normal isozyme with respect to stability, kinetics, and immunological properties. TPI 2HR1, an anodally migrating variant, was less stable than normal in guanidine denaturation and thermodenaturation tests, although it exhibited normal kinetic properties. The level of enzyme activity in erythrocytes from the proband with the phenotype TPI 1-2HR1 was about 60% of the normal mean. The variant allozyme TPI 2NG1, an anodally migrating allozyme associated with normal activity, was very thermolabile at 55 and 57 degrees C. It was also much more labile than normal in stability tests in buffers at pH 5 and pH 10, although it exhibited normal kinetic and immunological properties. TPI 4NG1, a cathodally migrating variant associated with normal activity and normal kinetic as well as immunological properties, was more stable than normal in pH 5 buffer. Family studies demonstrated that the unique characteristics of these variants are genetically transmitted. In two-dimensional electrophoresis of purified isozymes the variant subunits were separated from the normal in the pI axis. However, there is no difference between the variants and the normal in the molecular weight axis, suggesting that the variants result from single amino acid substitutions.

The rate with which spontaneous mutation alters the electrophoretic mobility of polypeptides

Studies of a Japanese population, involving a total of 539,170 locus tests distributed over 36 polypeptides, yielded three presumptive spontaneous mutations altering the electrophoretic mobility of the polypeptide. This corresponds to a mutation rate of 0.6 X 10(-5) per locus per generation. The a priori probability that undetected discrepancies between legal and biological parentage might in our test system result in an apparent electrophoretic mutation in this population is calculated to be only 0.3 X 10(-7) per locus per generation. Since electrophoresis only detects about half of the amino acid substitutions due to mutations of nucleotides, the corrected rate for mutations causing amino acid substitutions in polypeptides is 1.2 X 10(-5) per locus per generation. With allowance for synonymous mutations and those resulting in stop codons, the total mutation rate for nucleotide changes in the exons encoding a polypeptide becomes approximately equal to 1.8 X 10(-5) per locus per generation. When the present observations are combined with all of the other available data concerning mutation resulting in electrophoretic variants, the electrophoretic rate drops to 0.3 X 10(-5) per locus per generation, the total locus rate drops to roughly 1.0 X 10(-5), and the nucleotide rate drops to 1 X 10(-8). Even with this lower estimate, given approximately equal to 2 X 10(9) nucleotides in the haploid genome and an average of 10(3) exon nucleotides per polypeptide encoded, the implication, if these exon rates can be generalized, is of approximately equal to 20 nucleotide mutations per gamete per generation. This estimate of the frequency of "point" mutations does not include small duplications, rearrangements, or deletions resulting from unequal crossing-over, transcription errors, etc.

Electrophoretic variants of blood proteins in Japanese. IV. Prevalence and enzymologic characteristics of glucose-6-phosphate dehydrogenase variants in Hiroshima and Nagasaki

Electrophoretic screening of glucose-6-phosphate dehydrogenase (EC 1.1.1.49, G6PD) was conducted one sample of 9,260 children born to the atomic bomb survivors in Hiroshima (Honshu) and Nagasaki (Kyushu). The prevalence of electrophoretic variants was 0.11% in males and 0.42% in females in Hiroshima, and 0.16% in males and 0.31% in females in Nagasaki. Enzymologic characteristics of 10 variants obtained from three males and seven hemizygous fathers of heterozygous females were examined. As a result, three new types of G6PD variants were identified among five variants detected in Hiroshima, and three new types among five variants in Nagasaki. All the variants except one belonged to Class 3, as defined by Yoshida et al. (1971).

Inherited thermostability variants of seven enzymes in a Japanese population

The frequency of inherited variations in thermostability was investigated in a series of seven enzymes in a Japanese population. Among a total of 5930 determinations, nine variants were encountered. In each instance one parent exhibited a similar finding. It is suggested that this procedure should detect a high proportion of the variants of these enzymes characterized by amino acid substitutions not altering molecular charge. Failure to detect more such thermostability variants is interpreted to mean that electrophoresis not only detects amino acid substitutions altering molecular charge but also a considerable proportion of those that do not alter charge.

Electrophoretic variants of blood proteins in Japanese. III. Triosephosphate isomerase

A total of 15,387 individuals living in Hiroshima and Nagasaki, of whom 10,864 are unrelated, were examined for erythrocyte triosephosphate isomerase (TPI) by starch gel electrophoresis using TEMM buffer, pH 7.4. Four kinds of new variants, one having a cathodal migration and three having anodal migrations, were encountered in this population. These variants were further characterized by starch gel electrophoresis using tris-EDTA buffer, pH 9.3, and isoelectric focusing. An anodally migrating allozyme TPI 2HR1 exhibited markedly decreased enzyme activity, as evaluated by the staining intensity of the variant bands. The level of TPI activity in erythrocytes from this individual with the phenotype TPI 1-2HR1 was about 60% of the normal mean. Family studies confirmed the genetic nature of all the variants.

The frequency among Japanese of heterozygotes for deficiency variants of 11 enzymes

Eleven human enzymes, chosen for this study because of relatively small coefficients of variation for mean activity, have been surveyed for the frequency with which activities less than or equal to 66% of the mean value occur. This criterion should detect almost all heterozygotes for variants lacking any activity plus a fraction of the persons with variants characterized by markedly depressed activity and/or instability. The enzymes surveyed are TPI, PGK, AK1, LDH, GAPD, GPI, PK, 6PGD, G6PD, GOT1, and HK. The number of determinations per enzyme ranged from 310 to 3,173, for a total of 26,634 determinations. Family studies have thus far been possible in 52 instances in which the initial observation of activity less than or equal to 66% of normal was confirmed. In every instance, a parent exhibited a similar finding, giving confidence that a true genetic entity was being detected. With this approach, the frequency of heterozygotes per 1,000 determinations varied from 0.0 (AK1, 6PGD) to 13.8 (PK), with an average of 2.4. For these same systems, in this laboratory the frequency of "rare" electrophoretic variants is 2.3/1,000, the ratio of the latter to the former thus being 1.0 in Japanese. Our experience with these deficiency phenotypes to date suggests that for selected enzymes such phenotypes can be incorporated into a program designed to detect mutational events.

A phylogeny for the principal alleles of the human phosphoglucomutase-1 locus

The results of phosphoglucomutase-1 (PGM1) typings by starch gel electrophoresis and subtypings by isoelectric focusing are presented for a sample of Japanese. A distinction made on the basis of isoelectric focusing (termed "+" and "-") is nonrandomly associated with each of the products of the four most common electrophoretic alleles (PGM1(1), PGM1(2), PGM1(3), and PGM1(7). The isoelectric trait cosegregates with the allele; the degree of nonrandomness of the association varies from allele to allele. Thus, the four alleles become eight. On the basis of these facts plus the additive nature of the pI differences between allele products and the geographical distribution of the alleles, an allele phylogeny can be constructed. This postulates that the eight alleles may be explained by three nucleotide substitutions involving the stem allele plus four intragenic recombinations between these substitutions. The potential of intragenic recombination as a cause of mutation has been insufficiently appreciated.

Search for mutations affecting protein structure in children of atomic bomb survivors: preliminary report

A total of 289,868 locus tests, based on 28 different protein phenotypes and using one-dimensional electrophoresis to detect variant proteins, has yielded one probable mutation in the offspring of "proximally exposed" parents, who received an estimated average gonadal exposure of 31 to 39 rem in the atomic bombings of Hiroshima and Nagasaki. There were no mutations in 208,196 locus tests involving children of "distally exposed" parents, who had essentially no radiation exposure.

Variants of red cell enzymes found in Japanese of Hiroshima and Nagasaki

In the course of our search for possible genetic effects of radiation among the children of A-bomb survivors in Hiroshima and Nagasaki, we have obtained considerable electrophoretic data which clearly illustrate some of the genetic characteristics of the populations of both cities, which characteristics, however, have no relationship with radiation exposure of the parents. The frequencies of variants of phosphoglucomutase1 (PGM1) and glucose phosphate isomerase (GPI) were observed to be significantly higher in Nagasaki than in Hiroshima. As the difference in the frequencies of transferrin variants between two cities are also significant, it is apparent that the populations of the two cities are genetically different with respect to variation in certain protein systems.

Genetic heterogeneity within an electrophoretic phenotype of phosphoglucose isomerase in a Japanese population

The thermostability of the five kinds of electrophoretically variant phenotypes of GPI which were found in Japanese in a previous study (Tanis et al. 1977) was examined. The most frequently found variant phenotype, termed GPI 1-4HIR1, observed in 20 individuals could be divided into three distinct classes on the basis of thermostability characteristics. These classes were termed 'stable', 'labile', and 'very labile'. 'Stable' lost approximately 20 and 60% of its original activity after heating 10 and 30 min at 52-5 degrees C, respectively, while normal GPI lost approximately 30 and 70% of its original activity. 'Labile' lost approximately 40 and 80%, and 'very labile' lost approximately 55 and 90% of its original activity under the same heating conditions. Electrophoresis showed that that thermostability was a characteristic of the variant protein molecule but not of the electrophoretically normal molecule. The order of the stability of these three kinds of variants against 5 M urea was the same as that of their thermostability. No difference against inhibition by 6-phosphogluconate was observed among the normal and the variant phosphoglucose isomerases. Family studies confirmed the genetic nature of the thermo- and urea stability differences among the affected individuals.

The frequency in Japanese of genetic variants of 22 proteins. IV. Acid phosphatase, NADP-isocitrate dehydrogenase, peptidase A, peptidase B and phosphohexose isomerase

This paper presents the results of an electrophoretic survey of approximately 4000 individuals from Hiroshima and Nagasaki for four erythrocyte enzymes: isocitrate dehydrogenase, peptidase A, peptidase B, and phosphohexose isomerase. Also reported are the results for erythrocyte acid phosphatase for a subset of these individuals. The frequencies for the ACPA1 and ACPB1 alleles of the ACP1 locus are in agreement with previously reported results from Japanese populations. Rare variants of ICDS, PEPA, PEPB and PHI occur with frequencies varying from 0.25 to 7.2 per 1000 determinations. The relatively high frequency of the PHI 4HIR1 variant and some unusual features involving the effect of reducing agent on the electrophoretic pattern behaviour of some of the rare PHI variants detected during this study are discussed.

The frequency in Japanese of genetic variants of 22 proteins. III. Phosphoglucomutase-1, phosphoglucomutase-2, 6-phosphogluconate dehydrogenase, adenylate kinase, and adenosine deaminase

Five enzyme systems, PGM1, PGM2, ADA, 6-PGD and AK, were examined by electrophoresis in over 4000 samples from Hiroshima and Nagasaki for the frequencies of common and rare variants. In the PGM1 system, the PGM2(1) allele and PGM7(1) allele were found in polymorphic proportions, In addition, five kinds of slow variants and three types of fast variants of PGM1 were detected. The PGM3(1)NGS1 allele was found in five individuals from Nagasaki, but was not observed in samples from Hiroshima. There were no variants of PGM2. Three kinds of fast variants of 6-PGD were detected. No variation in AK was observed. There were no rare variants of ADA. The 6-PGDc allele had a frequency of 0.084 in Hiroshima and 0.093 in Nagasaki, and the ADA2 allele frequencies of 0.025 in Hiroshima and 0.032 in Nagasaki.

The frequency in Japanese of genetic variants of 22 proteins II. Carbonic anhydrase I and II, lactate dehydrogenase, malate dehydrogenase, nucleoside phosphorylase, triose phosphate isomerase, haemoglobin A and haemoglobin A2

This paper presents the results of a survey of Japanese for electrophoretic variants of CA I, CA II, LDH, MDH, TPI, NP, HB A and A2, the number of determinations per system ranging from 738 to 4029. Four similar variants of CA I (designed CA IHIR1), one of LDH (designated LDHNGS1), one of MDH (designated MDHS 7HIR1), two of HB A (one a reascertainment of HB Hijiyama, the other not characterized), and one characterized by the absence of HB A2 (delta-thalassaemia) were observed and are described. The CA IHIR1, LDHNAG1 and MDHS 2HIR1 variants have not been previously observed in Japan. No electrophoretic variants were found in the TPI and NP systems.

The frequency in Japanese of genetic variants of 22 proteins. I. Albumin, ceruloplasmin, haptoglobin, and transferrin

This paper presents the results of an electrophoretic survey of approximately 4000 individuals from the cities of Hiroshima and Nagasaki, Japan, for four serum proteins: albumin, ceruloplasmin, haptoglobin and transferrin. The haptoglobin gene frequencies obtained for the HP1-HP2 polymorphism are in agreement with earlier reports. Rare electrophoretic variants of albumin, ceruloplasmin and haptoglobin occur with frequencies of 2-48, 0-50 and 0-58 per 1000 determinations, respectively. The noteworthy finding of 8 distinct transferrin variants in these populations, with a combined frequency of 20-90 per 1000 determinations, is also presented. Four of these variants (Dchi, B1, B3, and DHIR2 which corresponds electrophoretically to D4) have been reported in other populations in Japan, but the other five have not previously been differentiated.

Production of mucopolysaccharides by normal and transformed cells

The rate of hyaluronic acid and sulfated mucopolysaccharide production was measured for hamster embryo fibroblasts and for general oncogenic lines derived by virus transformation. A striking increase in both the rate of hyaluronic acid synthesis and the amount of cell-associated polymer was observed after transformation by herpes simplex type-2 or SV40 virus. Although no corresponding change was observed for the sulfated polysaccharides, the proportion of heparan sulfate increased significantly after transformation.