Production of enkephalin in tobacco protoplasts using tobacco mosaic virus RNA vector

To examine the validity of the strategy to express a foreign gene as a fusion protein with the coat protein (CP) of tobacco mosaic virus (TMV), we have constructed ENK RNA by using an in vitro transcription system of TMV RNA. ENK RNA differs from TMV RNA only in that ENK RNA carries an additional sequence coding for Leu-enkephalin (Tyr-Gly-Gly-Phe-Leu) (Enk) with a preceding in-frame methionine just before the termination codon of CP gene. In protoplasts inoculated with ENK RNA, CP + Enk fusion protein accumulated as the major protein.

[Family study of primary hypercholesterolemia in school children--the Tsukuba Study]

Ninety-one children were determined to have hypercholesterolemia from a screening of 1,469 school children in the community near University of Tsukuba, and family studies of these children were performed. More than 50% of the parents participated in the study. The mean cholesterol levels of parents of hypercholesterolemic children were significantly higher than that of controls. Hypercholesterolemia in parents of hypercholesterolemic children was more frequent than that in controls. Nine families with autosomal dominant hyperlipidemia including familial hypercholesterolemia and familial combined hyperlipidemia were detected by further family studies. These results indicate that genetic factors are important as causes of hypercholesterolemia of school children and that family studies of hypercholesterolemic children is an efficient method for screening for persons with increased risk for cardiovascular diseases.

[Expression of oncogenes by smooth muscle cells in atherosclerotic lesions]

Smooth muscle cells in the thickened intima of the aorta also expressed sis, mye, and c-fos, in addition to collagen types I, III, IV and type V. In the cultures of smooth muscle cells isolated from human aorta, collagen I, III and gelatinase were produced without any other special conditions for the culture. In the presence of PDGF, collagen type V and collagenase production was detected in the culture. Oncogene expression was not detected in the cultured cells when tested by the indirect immunofluorescence technique. Immortalized smooth muscle cells with SV 40 expressed myc, SV 40 large T antigen, and p53 without inhibition of collagen and collagenolytic enzymes production.

Three novel partial deletions of the low-density lipoprotein (LDL) receptor gene in familial hypercholesterolemia

The low-density lipoprotein (LDL) receptor genes from 18 unrelated Japanese heterozygotes and 1 homozygote with classical familial hypercholesterolemia were analyzed by Southern blot hybridization using fragments of the human LDL receptor cDNA as probes. Four different deletion mutations were detected among 20 mutant LDL receptor genes (20%); they were characterized by restriction mapping. None of these mutations has previously been reported in Caucasian patients with FH: three of the mutations were novel and one was similar to the deletion mutation of FH-Tonami described previously in Japanese patients. In three of the four deletion mutations, the rearrangements were related to intron 15 of the LDL receptor gene, in which many Alu sequences exist. The data suggest that a wide range of molecular heterogeneity exists even in major rearrangements resulting in deletions in the LDL receptor gene. The data also support the hypothesis that there are preferential sites within the LDL receptor gene for major rearrangements resulting in deletions. The possibility that a higher frequency of deletion mutations occurs in classical FH than previously suspected is discussed.

Recombinant human erythropoietin produced by Namalwa cells

To establish a practical exogenous gene expression system in human cells, a cDNA coding for human erythropoietin (EPO) was expressed in human B-lymphoblastoid Namalwa cells. The Namalwa-derived recombinant EPO was purified from the culture fluid by a simple three-step procedure. The Namalwa EPO showed an equivalent activity in vivo to that of human urinary EPO. Oligosaccharide structure analyses suggested that almost all N-linked oligosaccharide chains of Namalwa EPO are shared by urinary EPO. The two major N-linked oligosaccharides of Namalwa EPO were fucose-containing tetraantennary and fucose-containing triantennary structures.

Cloning and nucleotide sequence of a flagellin-coding gene (hag) from Serratia marcescens 274

The pigmented enterobacterium Serratia marcescens shows a high frequency of color variation. In strain 274, color variation was shown to be closely associated with flagellar variation [Paruchuri and Harshey, J. Bacteriol. 169 (1987) 61-65]. As a first step towards understanding the genetic basis of this phenomenon, we have cloned and sequenced a flagellin-coding gene of S. marcescens 274. The gene codes for a protein product of 351 aa, with a predicted Mr of 36,862. Amino acid sequence comparisons reveal a high degree of homology between the N-terminal half and C-terminal third of the Serratia flagellin and flagellins from Escherichia coli and Salmonella typhimurium.

[Preoperative perspective versus postoperative functional assessment of surgery in chronic mitral regurgitation]

Thirty patients with chronic pure mitral regurgitation who underwent mitral valve replacement during 1981 to 1986 were evaluated for pre- and one year postoperative left ventricular function using two dimensional echogram. Indicators in their evaluation were DdI, DsI, MassI and systolic and diastolic R/Th. Postoperatively, patients (n = 7) were placed in a group of abnormal responses if even one of these indicators of left ventricular function became worse than preoperative performance, patients in this group were symptomatic and two subsequently died. The postoperative FS and mVcf data fort this group were significantly lower than the patients with normal response group (n = 23). These two groups could not be differentiated by preoperative assessments of either DdI, MassI, systolic/diastolic T/Th or normalized systolic/diastolic peak velocity. However, a combination of normalized systolic peak velocity lower than 1.70 and diastolic peak velocity lower than 2.20 of left ventricular wall motion proved to be good predictors of postoperative results.

Expression of human erythropoietin cDNA in human lymphoblastoid Namalwa cells: the inconsistency of a stable expression level with transient expression efficiency

Recombinant plasmids for the expression of human erythropoietin (EPO) cDNA in Namalwa cells were constructed. From the results of the EPO expression efficiency in transiently transfected cells, it was found that the simian virus 40 (SV40) early promoter directs EPO synthesis more efficiently in Namalwa cells than does the long terminal repeat promoter of Rous sarcoma virus and that the 3'-noncoding sequence including splice junction and polyadenylation site derived from the rabbit beta-globin gene are more effective than those of the SV40 early gene. However, in stable transformants, no simple relationship was found between the expression level of EPO cDNA and the structure of the introduced expression vectors.

An ultrasonographic method for detection of Achilles tendon xanthomas in familial hypercholesterolemia

The diagnosis of familial hypercholesterolemia (FH) is frequently made on clinical grounds and detection of tendon xanthomas is crucial for that. In order to clarify whether ultrasonography (US) can be used as a reliable and practical method for detection of Achilles tendon xanthomas in FH, the Achilles tendon thickness in the sagittal section was examined by US in 15 patients with heterozygous FH and 34 normocholesterolemic subjects. US visualized clearly the anterior and posterior borders of the Achilles tendon. The Achilles tendon thickness determined by US correlated with that measured by conventional radiography (r = 0.99). The mean values +/- SD of the Achilles tendon thickness determined by US were 4.5 +/- 0.5 mm in the normal controls and 11.9 +/- 5.1 mm in the patients and the difference was significant (P less than 0.001). In 13 of 15 patients, US visualized thickened Achilles tendons with convex shape in the sagittal section. All the thickened Achilles tendons revealed by US were confirmed by radiography. The data indicate that US can detect Achilles tendons thickened by xanthomas. We conclude that US is a useful aid in the clinical diagnosis of FH.

TaqI polymorphism in the LDL receptor gene and a TaqI 1.5-kb band associated with familial hypercholesterolemia

The low density lipoprotein (LDL) receptor gene was analyzed in 67 unrelated healthy Japanese and 38 members of six consecutive families with familial hypercholesterolemia (FH) by Southern blot hybridization with TaqI, an LDL receptor cDNA fragment containing exons 1 to 8 being used as a probe. A new TaqI RFLP at the LDL receptor locus was detected with allele frequencies of 0.67 and 0.33. The data obtained with smaller cDNA subfragment probes revealed that the TaqI RFLP site is located within 1.1 kb of the 5' side of the EcoRI site of exon 5. The TaqI RFLP was in linkage disequilibrium with the PstI RFLP but showed no significant linkage disequilibrium with the RFLPs for AvaII, ApaLI/I15, PvuII, NcoI, and ApaLI/3'. Among the seven RFLPs at the LDL receptor locus, the TaqI RFLP was the only useful genetic marker in one of the six families with FH. Furthermore, the association of an additional TaqI 1.5-kb band with a mutant LDL receptor gene was observed in another family with FH in which the proband was homozygous for all of the seven RFLPs. The data obtained with various restriction enzymes and smaller cDNA subfragments probes suggested that a minor change in nucleotide sequences in the region including exons 5 to 8 is present in the mutant gene. These data suggest that the TaqI RFLP is a useful genetic marker at the LDL receptor locus and that TaqI serves for the analysis of some mutant LDL receptor genes, when used with small LDL receptor cDNA probes.

Expanded selection criterion for Fontan's operation based on the size of distal pulmonary arteries

This study examined pulmonary arterial size to clarify a quantitative selection criterion for Fontan's operation in six cases without pulmonary hypertension. Pulmonary arterial size was angiographically assessed before and after the operation. No enlargement of the artery was observed, even after the procedure, confirming the importance of preoperative pulmonary arterial size. All three cases with preoperative PAa/N-RPAa of more than 0.5 survived the operation, whereas two of the remaining three cases (less than 0.5) died due to low cardiac output. The only survivor in the latter group had previously received Glenn's anastomosis. Hemodynamic study was done simultaneously, and a significant exponential correlation was obtained between preoperative PAa/N-RPAa and perioperative post-repair right atrial pressure (p less than 0.025). It was concluded that the selection criterion based on pulmonary arterial size could be expanded to a PAa/N-RPAa value of 0.5 when no Glenn's anastomosis had previously been done and the rudimentary right ventricle was not to be utilized. The exponential curve is useful for postoperative care in Fontan's operation, since it indicates the central venous pressure necessary to sustain the circulation at a level corresponding to the preoperative pulmonary arterial size.