岡山医学会Acta Medica Okayama0030-15581015-61989環軸関節の形態について673685ENKaoruBitohThe atlas and axis from 52 cadavers, 33 male and 19 female were measured from the outer contour and microradiographs of sectioned samples. The vertical diameter of the anterior arch of the atlas was 11.3mm in men and 10.9mm in women. The height of the body of the axis was 38.1mm in men and 33.8mm in women. The angle between the axes of the dens and the lower surface of the body of the axis was 58.6 degrees in men and 57.1 degrees in women. An anterior buttress plate to prevent atlanto-axial subluxation was designed based on the measurements of this study.No potential conflict of interest relevant to this article was reported.岡山医学会Acta Medica Okayama0030-15581015-61989HIV-1エンベロープ蛋白質の大腸菌での発現と精製659672ENBoZhangTo purify the HIV-1 envelope protein with antigenic reactivity, the Pvu II-Bgl II fragment of the HIV-1 env gene, from the Pvu II site to the second Bgl II site, encoding the carboxyl terminal 180 amino acids of the viral surface protein (SU, gp120) was molecularly cloned in Escherichia coli strain HB101 using protein A expression-shuttle vector pRIT5. The pRIT5 contains the protein A gene, encoding the secretion signal and IgG binding domain of protein A with the upstream promoter and the downstream multicloning sites, as well as the two replication sites for Escherichia coli and Staphylococcus aureus. A fused protein with the molecular weight of about 55 kilodaltons was produced, which showed the same reactivity as the native protein A against rabbit serum IgG on Western blotting analysis. Most of the fused protein in the periplasmic space was degraded, while the complete fused protein inside the cells was recovered as an insoluble protein. The fused protein was solubilized with sodium dodecylsulfate (SDS), partially purified by IgG sepharose affinity chromatography, and completely purified by SDS-polyacrylamide gel electrophoresis. The quantity of the expressed fused protein was estimated about 1% of the total proteins. The purified fused protein contained 516 amino acids with Mr54, 976, consisting of 305 amino acids of the IgG binding domain of protein A, 5 amino acids derived from polylinker, a carboxyl terminal 180 amino acids of the HIV-1 envelope surface protein gp120, and 26 amino acids derived from the pUC19 sequence.No potential conflict of interest relevant to this article was reported.岡山医学会Acta Medica Okayama0030-15581015-61989精神障害者の死亡と死因に関わる社会医学的要因647657ENHidetakaIeyasuMost previous studies of mortality among mental patients dealt only with an in-patient population or with in-patient and out-patient populations of a mental hospital. A communitybased study was performed to analyze the mortality among mental patients in Kochi Prefecture. Schizophrenics and alcoholics were selected out of all mental patients for analysis. The relative risk of death among male and female schizophrenics and male alcoholics were two or three times higher than that among the general population. Especially, a younger group (30-49 years old) had higher relative risk than an older group (50-79 years old) among both patients. Therefore, to decrease the mortality among the mental patients, it is important to provide adequate health and medical care to younger patients. Among male and female schizophrenics, high relative risks were found for suicide, heart disease and accidents. The relative risk of death among the female patients was higher than that among the male patients. Among male alcoholics, high relative risks of death were observed for liver cirrhosis, suicide, heart disease, accidents, pneumonia and cerebral vascular diseases. In conclusion, the development of a community mental health care system, as well as rapid progress in psychiatric pharmaco-therapy, is necessary to decrease the mortality among mental patients.No potential conflict of interest relevant to this article was reported.岡山医学会Acta Medica Okayama0030-15581015-61989水銀蒸気暴露後の生体内分布とエタノールの影響（水銀の酸化及び還元に関する試験管内及び動物実験 第3編）629646ENKouzirouKurahashiEthanol, 0.8 g/kg or 1.6 g/kg was administered to mice and exposed to mercury vapor ((203)Hg(0)) with the control mice which did not receive ethanol at the concentration of 0.1-0.5mg/m3 for 10 minutes. The exhaled mercury, urinary mercury, mercury in the blood and organ distribution of mercury after 1 hour of exposure of mice administered ethanol compared with those of control mice. The results obtained were as follows. 1. The amounts of exhaled mercury in the mice treated with ethanol were more than that in control mice; and the exhalations of human who receive ethanol will overestimate the true concentration of exposure in the Biological Monitoring. 2. The mercury concentrations in the blood of mice treated with ethanol were less than the control mice. The bloods of human who receive ethanol underestimate the true concentration of exposure in the Biological Monitoring. 3. The concentrations of mercury of urine corrected at a urinary density of 1.024 in mice treated with ethanol at 0.8 g/kg is more, and at 1.6 g/kg is less than the control. The urines of human who receive ethanol in low quantity will overestimate and in high quantity will underestimate the true concentration in the Boilogical Monitoring.
4. The concentrations of mercury of urine corrected at a urinary density of 1.024 have a significant regression to the mercury concentration in the kidney and not to the blood in all group (ethanol and control).No potential conflict of interest relevant to this article was reported.岡山医学会Acta Medica Okayama0030-15581015-61989水銀イオン投与後の生体内運命に関する(DL)-α-トコフェロール及びアミノトリアゾールの影響（水銀の酸化及び還元に関する試験管内及び動物実験 第2編）613627ENKouzirouKurahashiMice were preliminarily injected with Vitamin E subcutaneously and with mercuric ion intraperitoneally. The exhalation and organ distribution of mercury were determined and compared with the control mice without Vitamin E. Mice were preliminarily injected with 3-amino-l, 2, 4-triazole intraperitoneally and with mercuric ion intraperitoneally. The exhalation, urinary excretion and organ distribution of mercury were compared with the control mice. The results obtained were as follows. 1. The amounts of mercury in the exhalation of mice which were administered Vitamin E were more than the control. 2. The levels of mercury concentration and perecentages of distribution in the kidneys of mice which received Vitamin E were significantly higher than the control mice. The levels of mercury concentration and percentages of distribution in the carcass and the subcutaneous tissue of mice which received with Vitamin E were significantly less than the control mice, respectively. It suggested that the Vitamin E exerts an effect as the blocker, with accumulation of mercury in the adipose tissue and, eventually, a larger accumulation of kidney.
3. The amounts of exhaled mercury and that in urine in mice which received 3-amino-1, 2, 4-triazole were more than those in the control mice.
This suggested that the reoxidation of mercury (Hg(0)→Hg(++)) in the mice treated with 3-amino-1, 2, 4-triazole was less than in control mice, and that higher amounts of Hg0 resulted, which could be exhaled from the lungs and accumulated into the kidneys.No potential conflict of interest relevant to this article was reported.岡山医学会Acta Medica Okayama0030-15581015-61989(L)-アスコルビン酸，(DL)-α-トコフェロール，スーパーオキサイドアニオン及びマウス肝上清分画による水銀イオンの還元（水銀の酸化及び還元に関する試験管内及び動物実験 第1編）603612ENKouzirouKurahashiThe reduction of (203)Hg(++) by (L)-ascorbic acid, (DL)-α-tocopherol, superoxide anion and the supernatant of mouse liver homogenate after the ultracentrifugation were performed. The results obtained were as follows. 1. The relationships between the reductive rate of mercuric ion and the concentration of the (L)-AsA or (DL)-α-tocopherol were shown as a sigmoidal curve; that of the superoxide anion was a linear. 2. The activity of reduction of Hg(++) was in decreasing order with (L)-AsA, (DL)-α-tocopherol, and superoxide anion, respectively. 3. The liver homogenate was used with 8.5% sucrose and 11% polyvinylpirrolidone (PVP) solution with preparation of the homogenate to prevent release of catalase from the peroxisomes. Another preparation used 44mM phosphate buffer (pH 6.8) solution and the liver catalase was released from peroxisomes. The reductive rate of mercuric ion with the former preparation was 6.4 times higher than with the latter. It indicates that the reoxidation of metallic mercury by the catalase reduced the reductive rate of mercuric ion. 4. A reductive experiment of mercuric ion by liver supernatant containing sucrose and PVP at 0°C and 37°C was performed. The reduction rate by this sample at 0°C is 1/5.48 of that at 37° C. This suggests that the reduction of mercuric ion in liver homogenate is due to an enzymatic reaction.No potential conflict of interest relevant to this article was reported.岡山医学会Acta Medica Okayama0030-15581015-61989ヒト骨・軟部腫瘍における優性および劣性癌遺伝子の変異に関する研究589602ENToshifumiOzakiOsteosarcoma is a malignant bone tumor which usually occurs in the metaphysis of long bones in adolescents or young adults, but the mechanism of disease occurrence is unknown. To examine alterations in the dominant oncogenes in the osteosarcoma and other bone and soft tissue tumors, DNA extracted from 12 bone tumors, 12 soft part tumors and 2 cells lines was hybridized with c-oncogene (c-myc, c-sis, c-raf-1, c-fos, K-ras2, c-erbB, c-fms, c-fos). DNA extracted from the same samples was examined with Rb cDNA (p0.9R, p3.8R) probes, the retinoblastoma gene (Rb gene) localized at 13q14, to analize whether a recessive mutation is a target in osteosarcoma, and other bone and soft tissue tumors. Amplification of c-myc was observed in 3 cases from 7 osteosarcomas and abnormalities in structure of the Rb gene were found in 4 from 7 osteosarcomas, 2 from 4 MFH, and 1 from 2 Ewing's sarcomas. Both amplification of the c-myc and abnormalities of the Rb gene were observed in 3 osteosarcoma cases. The results indicated that both the Rb gene and c-myc oncogene may be involved in the initiation of osteosarcoma.No potential conflict of interest relevant to this article was reported.岡山医学会Acta Medica Okayama0030-15581015-61989肺扁平上皮癌の治療に関する研究 第2編 ヒト肺扁平上皮癌細胞株を用いた温熱化学療法に関する検討581588ENTakumiSetoThe effectiveness of hyperthermia in combination with anticancer drugs on EBC-1 cell line established from a patient with pulmonary epidermoid carcinoma was investigated. Anticancer drugs tested in the present study were adriamycin, bleomycin, cisdichlorodiammineplatinum (II) and mitomycin C. EBC-1 cells were incubated with the drug for one hour at 37°C or at elevated temperature (41°C, 42°C and 43°C). The enhancement of cytotoxicity by hyperthermia was found in combination with all of the drugs. The degree of enhanced cytotoxicity was positively elated to the temperature in combinations with adriamycin and bleomycin. Especially, a synergic enhancement of cytotoxicity was found with the combination of hyperthermia and bleomycin. The present study showed that the combination of hyperthermia and anticancer drugs produced potential cytotoxicity on EBC-1 cells in vitro, and may provide useful information for the clinical trials in the future.No potential conflict of interest relevant to this article was reported.岡山医学会Acta Medica Okayama0030-15581015-61989肺扁平上皮癌の治療に関する研究 第1編 ハムスター移植ヒト肺扁平上皮癌細胞株に対する各種制癌剤の感受性について573580ENTakumiSetoChemotherapy is the only therapeutic modality applicable to patients with advanced pulmonary epidermoid carcinoma (PEC). However, the results of chemotherapy to PEC remain unsatisfactory. It is very important to have an accurate knowledge of the sensitivity of anticancer drugs against PEC in order to establish a successful chemotherapy. The in vivo sensitivity of 12 anticancer drugs was investigated using PEC cell line (EBC-1) xenografts in hamsters.
In the present study, adriamycin, ifosphamide, mitomycin C, methotrexate and cisdichlorodiammineplatinum (II) showed antitumor activity against EBC-1 cells, but the other 6 drugs (ACNU, bleomycin, 5-fluorouracil, neocarzinostatin, procarbazine and vincristine) have no antitumor activity against EBC-1 cells. These results suggest that combination chemotherapy with 3 or 4 drugs with antitumor activity in the present study may be effective to PEC.No potential conflict of interest relevant to this article was reported.岡山医学会Acta Medica Okayama0030-15581015-61989リスザルレトロウイルスLTR関連ヒト遺伝子の分子クローニングと構造解析557571ENKazutakaNagaoSequences related to the squirrel monkey retrovirus (SMRV) LTR were isolated from a genomic library of human DNA by screening under conditions of relaxed stringency. The probe contains several transcriptional signals and its regulatory sequences in SMRV-H LTR, such as the enhancer sequence, CAT box, TATA box, and polyadenylation signal. More than 50 positive signals were detected in 4.4×105 recombinant phages. The cloned human sequences named SRH strongly hybridized with SMRV-H LTR and some of them weakly hybridized with SMRV-H structural genes. In SRH-1, the region related to SMRV-H prt-pol-env was flanked by the two separately located sequences related to the LTR. SRH-3 has a solitary LTR-related region, whereas, in SRH-5, the LTR-related region was adjacent to the pol-env-related sequence. The reliability of these hybridization experiments was confirmed by reciprocal hybridization. The restriction enzyme cleavage maps of these clones were different from those of known human endogenous retroviruses. Alu sequences, a human highly repetitive sequences, were inserted to the LTR-and pol-env-related regions in SRH-5.No potential conflict of interest relevant to this article was reported.岡山医学会Acta Medica Okayama0030-15581015-61989VDT作業時のキーボード高と肩腕部筋負担に関する研究541555ENToruOtaniElectromyograms (EMG) during Japanese and English word processing work with various keyboard heights was recorded and analyzed with amplitude probability distribution methods, in order to examine the effect of keyboard height on local muscular load in the shoulder and forearm regions. The EMG was recorded from the extensor carpi radialis brevis muscles, the trapezius muscles and anterior and medial portion of the deltoideus muscles. The keyboard height was placed at 5cm below elbow, elbow height, 10cm above elbow and height selected by the examinee. Eight young female students volunteered to participate in this experimental study. According to the results of the EMG amplitude probability distribution analysis, keyboard height gave different loads to the respective muscles. For example, the load to the extensor carpi radialis brevis muscles decreased as the keyboard position became higher, while the load of trapezius muscles increased. In conclusion, it was suggested that there is no best keyboard height during VDT work from the view point of muscles load. Therefore the keyboard height should be adjusted considering the characteristics of individual VDT work and the muscles fatigue of the operator.No potential conflict of interest relevant to this article was reported.岡山医学会Acta Medica Okayama0030-15581015-61989土呂久における慢性ヒ素中毒認定患者の悪性新生物についての疫学的研究529540ENToshihideTsudaAn epidemiological study has been made to assess the carcinogenic effect of arsenic exposure by analyzing a group of patients with certified chronic arsenic poisoning at “Toroku”, a small mountainous village in Japan. The number of deaths from cancer of the respiratory system and cancer of bladder, kidney and other and unspecified urinary organs showed a significant excess over the expected value, compared with expected number of deaths, based on sex and age-specific mortality of Japanese in 1975, 80 and 85. The number of patients from all cancers, respiratory cancer and urinary tract cancer showed a significant exess of former workers, using data classified by employment history. Classified by employment history and smoking habits, the number of respiratory cancers showed a significant excess only in the cohort of former workers with a smoking history. This finding suggests that there is an interaction between exposure to arsenic and smoking. Eleven of seventeen cancer cases were accompanied by cancer of other organs, including Bowen's disease. These results demonstrated that a follow-up study on these patients should be conducted with a particular emphasis on cancers.No potential conflict of interest relevant to this article was reported.岡山医学会Acta Medica Okayama0030-15581015-61989内因性，外因性カテコルアミンのイヌ摘出交叉灌流心臓の収縮性および酸素消費量に及ぼす影響に関する実験的研究517528ENYuichiOhgoshiThe author studied the effects of circulating catecholamines (CA) on both the left ventricular (LV) contractility index (Emax) and the relationship between LV O(2) consumption (VO(2)) and systolic pressure-volume area (PVA) in 11 excised cross-circulated dog heart preparations. Adrenal medullary stimulation (AMS) of the support dog caused frequencydependent increases in circulating CA. The correlation between the increases in Emax and CA was statistically significant in each heart preparation, but the sensitivity of Emax to CA varied widely. The VO(2)-PVA data point under fixed LV end-diastolic and stroke volumes moved linearly right-upward with increases in Emax. The slope of the VO(2)-PVA locus was steeper than the slope of the reference VO(2)-PVA relationship in control contractility. An infusion of exogenous epinephrine produced similar results to that obtained in the AMS run. The present results indicated a similarity between the effects of endogenous and exognenous catecholamines on both Emax and the elevation of the VO(2)-PVA relation in each heart preparation with a variability in the sensitivity of the elevation of the VO(2)-PVA relationship varied widely among the individual hearts.No potential conflict of interest relevant to this article was reported.岡山医学会Acta Medica Okayama0030-15581015-61989Human tumor clonogenic assayを用いた制癌剤感受性試験とnatural human Tumor Necrosis Factorの抗腫瘍効果に関する研究505515ENKanjiOkamotoThe human tumor clonogenic assay is a test of susceptibility to anticancer drugs which is known to correlate well with clinical effects. In this report, this assay was used to study the antitumor effects of several anticancer drugs and human tumor necrosis factor-α (nHuTNF-α), and the combination effect of nHuTNF-α and natural human interferon-α (nHuIFN-α). Susceptibility to exisiting anticancer drugs was studied in 94 cases involving 92 patients. Colony formation was obtained 50 cases (53.2%). Of these, susceptibility to ADM was found in 15 cases, to MMC in 8 cases and to 5-Fu in 11 cases. When the antitumor effect of nHuTNF-α was studied in 10 cases obtained from patients with malignant tumor, colony inhibition was shown in 9 cases of more than 30% with 100 units and more than 50% with 300 units. A synergistic effect was assessed with a combination of nHuTNF-α and nHuIFN-α against 4 cell lines (KB, Hep-2, KATO-III, PC-9). The results showed a synergistic effect in KB and Hep-2 cell culture system. From these results, nHuTNF-α seemed to be effective anticancer drugs. The synergistic antitumor effect may be expected if the combination of nHuTNF-α and nHuIFN-α was used clinically.No potential conflict of interest relevant to this article was reported.岡山医学会Acta Medica Okayama0030-15581015-61989Menkes症モデルマウス (Macular mouse) でのMetallothionein mRNAの調節495503ENMitsumasaKajiMT-mRNA levels in tissue were measured in normal and macular mutant mice. The MT-mRNA level in tissues (kidney, intestine, liver, brain, spleen, thymus, lung and heart) of 7-day-old mutants was not changed compared to normal mice. Kidney MT-mRNA levels in the mutant foetus at 18 days of gestation and in the 3- and 7-day-old mutant were not changed compared compared to normal mice, with the exception of the 1-day-old mutant. Intestine and liver MT-mRNA levels in the mutant foetus at 18 days gestation and in the 1-, 3- and 7-day-old mutant were not changed compared to normal mice.No potential conflict of interest relevant to this article was reported.岡山医学会Acta Medica Okayama0030-15581015-61989先天性心膜欠損症における心臓超音波所見（体位変換による所見の変化）487494ENKazuyoshiHinaMasayukiUeedaShinjiUchidaMasahiroHasuiTsutomuMimaHirofumiWatanabeDaijiSaitoTakaoTsujiKatashiMatubaraHidenoriYoshidaShoichiHaraokaKohichiroIwasakiShozoKusachiToshimasaKitaThe true incidence of congenital pericardial defects is unknown, but it is more common than generally supposed. Because of the variance of chest X-rays, ECG and symptoms according to the degree of the defect, it is still not easy to diagnose a pericardial defect. Recently, we experienced four patients with congenital pericardial defects. Three cases were absence of the left pericardium and one was an absence of the right. In these patients, the view with echocardiography was characteristically altered by posture changes. All three patients with left-sided defect showed an enlarged right ventricular cavity, paradoxycal motion of the interventricular septum and hyperkinetic motion of the posterior wall in the left lateral decubitus position. These findings were not present in the right decubitus position. On the other hand, in a case with a right-sided defect, the view was almost normal in the left decubitus position. In the right decubitus position, the right ventricular cavity enlarged and the interventricular septum moved hyperkineticaly. These alterations of echocardiographic findings by posture changes were specific to the side of the pericardial defect, and were caused by a change in cardiac restraint. Therefore, an echocardiogram recorded with posture changes is useful in the diagnosis of congenital pericardial defects.No potential conflict of interest relevant to this article was reported.岡山医学会Acta Medica Okayama0030-15581015-61989アカタラセミアマウスに一酸化窒素，二酸化窒素曝露時のメトヘモグロビン生成473488ENKunihikoIshiiThe formation of methemoglobin from hemoglobin in the hemolysates and erythrocytes of normal and acatalasemic mice was studied by exposure to nitric oxide and nitric dioxide. The data indicated that the ratio of methemoglobin formation in acatalasemic mice is larger than that in the normal mice in every case, and nitric oxide has a stronger action compared to nitric dioxide in regard to methemoglobin formation. The results indicated that hemoglobin is changed to methemoglobin through nitrosylhemoglobin with nitric oxide, and catalase has an inhibiting action on this oxidation process.No potential conflict of interest relevant to this article was reported.岡山医学会Acta Medica Okayama0030-15581015-61989ヒト免疫不全ウイルス抗原の免疫電子顕微鏡的研究459471ENSatoruEndoImmunoelectron microscopic observations of human immunodeficiency virus (HIV) antigens were made using the indirect peroxidase-labeled antibody method with monoclonal antibodies (MoAb) to the envelope glycoprotein (gp160/120), matrix protein (MA, p17), and capsid protein (CA, p24). Antigens in the virions and HIV-infected cells were detected in frozen-sectioned specimens. Positive immunoreaction of MoAb to gp160/120 was located on the viral envelope, plasma membrane, endoplasmic reticulum, and nuclear membrane. The reaction of MoAb to p17 was at the inner leaflet of the viral envelope and the nucleoid. The reaction of MoAb to p24 was localized on and around the viral core. In cell suspension, however, positive immunostaining was observed only on the surface of the viral envelope and plasma membrane with MoAb to gp160/120, and no positive staining was observed with MoAb to p17 and MoAb to p24. The reaction of HIV-infected cells with normal control serum and all of the reactions in uninfected cells with these MoAbs were negative. It appears that antibodies have difficulty penetrating into virions and cells in cell suspension.No potential conflict of interest relevant to this article was reported.岡山医学会Acta Medica Okayama0030-15581015-61989市街地大気汚染測定局の地域代表性に関する研究447457ENFukuichiFujiwaraIn order to evaluate the representativeness of a monitoring station for nitrogen dioxide in an urban area of Okayama City, the nitrogen dioxide concentration was measured in the area six times between 1982 and 1984. The area was divided into 96 sections and the concentration of nitrogen dioxide was measured at the central part of each section and at a continuous monitoring station located in the area. From the measured values, the distribution of nitrogen dioxide concentration levels was determined and the correlation coefficients of the levels at the measuring points were calculated. The results show that the nitrogen dioxide concentration levels vary according to the direction and strength of wind, and other factors, but the levels of nitrogen dioxide at the continuous monitoring station were close to the mean level of the 96 measuring points throughout all observation days. The correlation coefficients between the nitrogen dioxide levels at the continuous monitoring station and those of the other 96 measuring points were large. It can be concluded that the present continuous monitoring station is one of the best points to monitor nitrogen dioxide concentration in the urban area of Okayama City.No potential conflict of interest relevant to this article was reported.岡山医学会Acta Medica Okayama0030-15581015-61989Lactobacillusにおけるカドミウム耐性機構の解析437446ENYasuoKatayamaThe cadmium resistance of Lactobacillus and its mechanism were examined, with the following results: (1) The 16 strains of Lactobacillus were classified into two groups: 6 strains which were sensitive to cadmium and 10 strains which were resistant to more than 1mM cadmium. (2) All cadmium sensitive strains belonged to L. plantarum and L. fermentum species, and all cadmium resistant strains were L. casei and L. acidophilus species. (3) The barrier to cadmium influx in cadmium resistant strains showed no difference between L. casei and L. acidophilus strains. (4) The cytoplasmic cadmium contents in L. casei were higher than those in L. acidophilus, and there was a significant difference between L. casei and L. acidophilus (P<0.01). (5) From these results, L. casei appears to possess a mechanism for the detoxication of cytoplasmic cadmium using cadmium binding proteins and L. acidophilus appears to have a mechanism for pumping out cytoplasmic cadmium.No potential conflict of interest relevant to this article was reported.岡山医学会Acta Medica Okayama0030-15581015-61989ヒトゲノムDNA中のリスザルレトロウイルス関連遺伝子の検出423435ENHirohikoAsonumaSquirrel monkey retrovirus (SMRV) is an endogenous type D retrovirus of the squirrel monkey, a New World primate. Southern hybridization with cloned SMRV-H revealed that 3040 copies of SMRV proviral DNA are present in the squirrel monkey genome and the majority have almost the same physical map as that of the cloned SMRV-H. SMRV-related sequences in the human genome were sought using the same method with various cloned SMRV-H DNA fragments under conditions of relaxed stringency. The discrete restriction fragments were frequently detected in the DNA from normal humans with the LTR and parts of gag and env as probes. Since SMRV LTR has very little homology with the LTRs of other retroviruses, the fragments detected with the LTR probe were characterized as SMRV-related human sequences. SMRV LTR-related sequences were also detected in the African green monkey and chicken, but not in the salmon, mouse, or dog. In conclusion, SMRV-related sequences are present in human DNA, and some of them might represent endogenous retroviral sequences of human DNA.No potential conflict of interest relevant to this article was reported.