Molecular mechanisms of nucleotide-sequence rearrangements in cDNA clones of human fibroblast interferon mRNA

The characterization and nucleotide sequencing of cDNA clones of human fibroblast interferon (HFIF) mRNA (Derynck et al., 1980) revealed two types of structural inversions :(i) an inverted repeat of a 3'-proximal segment at the 5'end, or (ii) an inverted 5'-terminal segment. Based on the nucleotide sequence of these inverted clones, we have deduced molecular mechanisms to explain how the rearrangements could have arisen. We propose that the usual small 3'-terminal hairpin does not form after the reverse transcription produces the first cDNA strand. Instead, base pairing occurs between the 3'-terminal segment and the more distal region of the first cDNA strand, forming a much larger hairpin loop. Second-strand synthesis followed by either nicking or unfolding of the loop structure and continuation of the polymerase reaction would lead to the observed types of inversions. The 5'-truncated clone, pHFIF-1, whose new 5'-terminal sequence diverges from that of the corresponding region in the mRNA, can also be explained by such a mechanism.

Leiomyoma and leiomyosarcoma of the digestive tract--a report of 45 cases and review of the literature

The authors discuss the general and radiologic characteristics of leiomyomas and leiomyosarcomas, based on experience with forty-five cases involving the digestive tract and a review of over one thousand cases reported in the literature. Thirty-six leiomyomas (oesophagus 9, stomach 18, small intestine 9) and nine leiomyosarcomas (oesophagus 2, stomach 2, small intestine 4, colon 1) were observed and compared with reports from the literature. Leiomyomas of the oesophagus lend themselves to radiologic surveillance since there is no tendency for lesion degeneration in this location. Leiomyomas of the stomach are frequently asymptomatic and discovered following radiologic or endoscopic examination. With involvement of the small intestine, the most sensitive radiologic examination remains angiography, even though the information provided does not allow evaluation of the evolution of the tumour. Localization in the colon remains rare.

[Critical evaluation of non-biological complementary examinations of the biliary tract before deciding on therapy (author's transl)]

A critical evaluation of non-biological complementary examinations of the biliary tract was conducted to assess their value when deciding on therapy. The published literature was reviewed, and the sensitivity and specificity of the different methods presented, emphasis being placed on the primary investigations of ultrasonography and oral and intravenous biligraphy. Secondary exploratory procedures (transparietal cholangiography, retrograde endoscopy with cholangiography and pancreatography, scintigraphy, gallbladder infusion parietography, scanography, and arteriography) are defined and their value discussed. Published data suggest that ultrasonography should be the initial investigation, this often being sufficient to enable suitable therapy to be chosen. Only approximately 5 p. cent of patients are unable to benefit from gallbladder exploration, and these require conventional radiological examinations before deciding on therapy.

Nucleotide sequence of the chromosomal gene for human fibroblast (beta 1) interferon and of the flanking regions

The nucleotide sequence of the human fibroblast (beta 1) interferon chromosomal gene and its flanking regions was determined. These results confirm the absence of intervening sequences in the gene. The presence of some sequences in the upstream flanking region homologous to similar features for other eukaryotic genes was revealed: these include not only the TATAAAT sequence and the consensus sequence (reported by Benoist et al., 1980) but also two additional motifs, one of which is so far present only in inducible genes. Furthermore, a striking similarity between the upstream flanking regions of the human beta 1 and alpha 1 interferon genes is observed.

Evidence for a unique human fibroblast interferon (IFN-beta 1) chromosomal gene, devoid of intervening sequences

Direct restriction analysis of the human genome, using the Southern transfer technique and hybridization with a human fibroblast interferon (IFN-beta) complementary DNA insert probe, revealed the presence of a single gene; no additional closely related IFN-beta genes could be detected. A lambda-linked human gene library (Lawn et al., Cell, 15, 1157-1174 (1978)) was screened using the cDNA probe. Out of 600,000 recombinant phage examined, one single clone bearing interferon sequences was obtained. Restriction analysis of the relevant region revealed an identical restriction map as obtained for the IFN-beta 1 cDNA clones. No intervening sequences could be detected, either in the coding or the non-coding regions of the gene.

Isolation and structure of a human fibroblast interferon gene

Chimaeric plasmids containing double-stranded cDNA copies of mRNA induced in human fibroblasts by poly I . C were screened by an RNA selection method. A series of clones to which human fibroblast interferon mRNA selectively hybridized was identified. From the nucleotide sequence of the gene, the complete amino acid sequence of human fibroblast interferon was deduced. The protein is 166 amino acids long and is preceded by a 21-amino acid signal sequence.

[Bronchocele. A radiological study from 5 cases (author's transl)]

Bronchocele present a characteristic radiological appearance. Their significance varies according to the clinical context:--a picture of diffuse bronchopathy with mucoid impaction would suggest a medical treatment;--in the absence of any bronchopathy the X-ray should seek a under-jacent lesion which would respond to surgery.

[Congenital malformations of the inferior vena cava. Embryological, anatomical and radiological study (author's transl)]

Congenital malformations of the inferior vena cava are characterized by their diversity which is related to the complexity of the embryological development of this vessel. The authors review the embryogenesis and origin of the different segments of the inferior vena cava and describe the various types of malformation, including the causative embryological abnormality, ther frequency, possible clinical repercussions, and radiological aspects. Phlebocavography is essential for the identification of the various types of abnormality. Five different types of malformation are reported. Three of these are relatively rare (left inferior vena vaca, congenital membrane of the inferior vena cava, absence of the hepatic segment with continuation of the isolated azygos segment).

[Inferior mesenteric arteriovenous fistula of congenital origin. A report on one case and review of the published literature (author's transl)]

A fourth case of inferior mesenteric arteriovenous fistula of congenital origin is described by the authors, who also review the general characteristics of mesenteric (or portal) arteriovenous fistulae. Early clinical signs are hemorrhage from the digestive tract and chronic anemia. Endoscopy and barium X-rays are normal, and angiography is the only means of diagnosis. Surgical treatment is essential because of the risk of hemorrhages and portal hypertension.

[Arterial hypertension and horseshoe kidney during Von Recklinghausen's disease. Angiographic study and review of the literature (author's transl)]

Angiographic studies in a young girl aged 16 years who developed arterial hypertension during the course of Von Recklinghausen's disease, demonstrated the presence of an obliterated renal artery in a horseshoe kidney. The distal arterial segment was revascularized by two homolateral ureteral arteries. A full review of the literature revealed 30 cases of renal artery lesions for which angiography had been carried out in young people with neurofibromatosis. This demonstrates the low incidence of obliterative lesions (4 cases throughout the world) which are always associated with collateral vascularization. It was not possible to apply the usual surgical treatment in our case because of the associated horseshoe kidney.

[Triple ureter. One case. Diagnostic problem and review of the literature (author's transl)]

In the light of a case of right triple ureter in a 5 month old girl, the authors review the embryology of the ureter and describe the different types of triplication. A general review of the literature including 70 cases gives an indication of the circumstances of discovery and the contribution of radiology. The complications of complete ureteral triplication are the same but greater than those of complete duplication and are related to the ectopic position of the ureteral orifices with regard to the trigone. They are dominated by reflux and stasis in the case of high ectopia and by false incontinence (20% of cases) in low ectopia.

[Renal vein thrombosis in the newborn infant]

In a child born with traumatism to a diabetic mother, an acute thrombosis of the left renal vein occurred. An arteriography performed at the acute stage, established the diagnosis. The newborn received urokinase and heparin administered through an arterial catheterism. An arteriography, repeated at the 3rd day, showed an improvement in the vascularization of the kidney, which returned to normal functions. The radiological symptons of renal vein thrombosis are reviewed including the arteriography which is never used for the diagnosis in newborns. The interest of the use of urokinase and its efficiency in this disorder are discussed. This therapy harmless and efficient seems of interest. Such a therapy has to be tried because of the failure of isolated heparin-therapy and of the sequellae which may be observed after spontaneous recovery or after anticoagulant treatment.