Sequence and expression of Paracentrotus lividus alpha tubulin gene

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Postpartum coronary artery dissection followed by heart transplantation

A rare case of coronary artery dissection was observed in a 33-year-old woman on the fourth postpartum day. The ischemic syndrome was followed by aneurysmal dilatation of the left ventricle and progressive heart failure that necessitated cardiac transplantation. The patient is alive and well 3 years after the transplantation.

Cis-acting elements of the sea urchin histone H2A modulator bind transcriptional factors

Functional tests, performed by microinjection into Xenopus laevis oocytes, show that a DNA fragment containing the modulator of the early histone H2A gene of Paracentrotus lividus enhances transcription of a reporter gene when located, in the physiological orientation, upstream of the tk basal promoter. Gel retardation and DNase I footprinting assays further reveal that the H2A modulator contains at least two binding sites [upstream sequence elements 1 and 2 (USE 1 and USE 2)] for nuclear factors extracted from sea urchin embryos, which actively transcribe the early histone gene set. Interestingly, USE 1 is highly homologous to a cis-acting element previously identified in the H2A modulator of Psammechinus miliaris [Grosschedl, R., Mächler, M., Rohrer, U. & Birnstiel, M. L. (1983) Nucleic Acids Res. 11, 8123-8136]. Finally, a cloned oligonucleotide containing the USE 1 sequence competes efficiently in Xenopus oocytes with the H2A modulator to prevent enhancement of transcription of the reporter gene. From these results, we conclude that USE 1 and perhaps USE 2 in the H2A modulator are upstream transcriptional elements that are recognized by trans-acting factors common to Xenopus and sea urchin.

Interleukin-2, interleukin-2 receptor and gamma-interferon synthesis by peripheral blood mononuclear cells in chronic hepatitis delta virus infection

The behaviour of the immune system during liver damage caused by chronic hepatitis delta virus (HDV) infection was evaluated by assessing, in 16 patients with HBsAg+ chronic liver disease and HDV superinfection (15 HBeAg-, 1 HBeAg+), phytohaemagglutinin (PHA)-induced interleukin-2 synthesis and interleukin-2 receptor expression, PHA and staphylococcal enterotoxin B (SEB)-induced gamma-interferon synthesis and, in some cases, the presence of hepatitis B virus DNA (HBV-DNA) within peripheral blood mononuclear cells (PBMC). The results were compared to those obtained in 13 patients without HBV replication (i.e., serum HBV-DNA and liver HBcAg-negative), in 15 with HBV replication (i.e., serum HBV-DNA and/or liver HBcAg-positive) with chronic liver disease without HDV superinfection, and in 15 HBsAg-negative healthy control subjects. The lymphokine pattern in HDV infection was comparable to that of healthy subjects and of HBV non-replicating patients without HDV superinfection. Interleukin-2 receptor expression and gamma-interferon synthesis were however significantly decreased in HDV-negative patients with active HBV replication. HBV-DNA was detected in PBMC from 8 of 23 patients, without any correlation with the lymphokine pattern. Our results suggest that in HDV-related chronic liver disease, immune system alterations are unlikely. HDV superinfection does not affect the occurrence of HBV-DNA sequences within the leukocytes. HBV-DNA in PBMC does not interfere with the interleukin-2 system nor with the gamma-interferon response in HBV- and HDV-related chronic liver disease.

DNA sequence and pattern of expression of the sea urchin (Paracentrotus lividus) alpha-tubulin genes

To study the molecular aspects of the regulation of transcription of a multigene family, we have isolated and sequenced cDNA and genomic clones coding for the alpha-tubulin of the sea urchin Paracentrotus lividus. Two cDNA clones, P alpha 10 and P alpha 4, contain respectively the coding information for 391 C-terminal and for 338 N-terminal amino acids of the 452 residues that constitute the complete protein. They show silent nucleotide substitutions only, suggesting that P alpha 10 and P alpha 4 represent the cloned copies of two allelic gene transcripts, which encode for two alpha-tubulin isoforms with identical amino acid sequence in the region of the overlap. The comparison of the predicted amino acid sequence of the composite P alpha 4-10 and of the mouse M alpha-6 (Villasante et al., Mol Cell Biol 1986; 6:2409-2419) reveals a conservation of 97% between the two polypeptides. By RNA blotting hybridization six major alpha-tubulin transcripts were identified. Two, of 3.5 kb and 2.0 kb, are expressed in the unfertilized eggs and during early cleavage. The other two maternal mRNAs, of 2.4 kb and 1.8 kb, are expressed in both early and late cleavage embryos, but in the intestine the 1.8 kb RNA, which specifically reacted with the 3' specific probe of the P alpha 10 cDNA, is the only transcript detected. Finally, the 1.5 kb and 1.9 kb mRNAs represent the transcription of stage- and tissue-specific genes, respectively. In fact, the former becomes detectable at blastula stage and accumulates during late development, whereas the latter is found in the testis only. The sequence data of the 3' terminus of the alpha-3 genomic clone suggests that it encodes for a divergent alpha-tubulin, and it most probably corresponds to the testis-specific gene.

BREASTCAN: an expert system for postoperative breast cancer therapy

An expert system, named BREASTCAN and designed to assist physicians giving postoperative adjuvant chemotherapy for breast cancer, is described. The system is based on frames, each corresponding to one stage of treatment--either a decision-making stage or a therapeutic stage. The system has been designed to allow fast and easy consultation by general practitioners lacking computer knowledge.

Different micrococcal nuclease cleavage patterns characterize transcriptionally active and inactive sea-urchin histone genes

The micrococcal nuclease cleavage sites have been mapped in the H2A coding and flanking regions of the sea-urchin histone DNA chromatin. A hypersensitive area, centered around - 100 base pairs from the H2A starting site, is found only in embryos actively transcribing the alpha-subtype histone genes. In mesenchyme blastula embryos, upon inactivation of the H2A gene, this region becomes protected while two other areas, near the transcription starting site and in the proximity of the 3' palindromic sequence, become preferential targets for the enzyme. Analysis of the pattern of micrococcal nuclease cleavage on the same region of the histone gene cluster in sperm and late blastula chromatin and on the corresponding segment of protein-free DNA indicates that distinct nucleosomal arrangements characterize the histone genes in the two cell populations.

Functional activity and chromatin configuration of SV40 enhancer injected in Xenopus laevis oocytes

The SV40 enhancer microinjected into the nuclei of X. laevis oocytes is able to activate transcription about 100-fold when cloned upstream of the SV40 early promoter region or about 10-fold regardless of its orientation when located at a long distance from a test gene (bacterial chloramphenicol acetyl transferase). This effect is qualitatively and quantitatively similar to that observed when analogous constructions were transfected into mammalian cells. Making use of a direct labelling technique for the analysis of the chromatin structure we could show that the SV40 enhancer region in the microinjected plasmids is particularly accessible to cleavage with MNase or DNAse I. Single sites in the 72 bp repeats have been mapped at the nucleotide level.

Comparing continuous and stepwise luminance variation in static campimetry using the Grignolo-Tagliasco-Zingirian projection campimeter

In traditional static perimetry the remarkable precision achieved, resulting mainly from the lack of temporal factors related to latency, largely makes up for the relatively long time required to perform the test. Conversely, the increase in speed of the test and in the information content of the visual field charts counteract the lower precision attained with kinetic perimetry. If the influence of the latency time on responses could be kept at a low value, then adopting a static strategy, based on a continuous rather than discrete target luminance variation for threshold detection, could be justified. For this purpose a luminance variation time sequence designed to reproduce the conditions of the traditional static perimetric test was chosen. The test was performed on the Grignolo-Tagliasco-Zingirian projection campimeter, after comparing its clinical performance with the Goldmann perimeter. These two methods - one based on continuous variation, the other based on discrete target luminance variation - were compared using a 14-subject sample. We conclude that the presentation strategy based on continuous luminance variation can be regarded as a valid alternative to the traditional method.

[Limitations of the stress test in the diagnosis of the sick sinus syndrome]

Exercise stress test in patients with sick sinus syndrome helps to evaluate the heart rate response to the increased sympathetic and to the decreased parasympathetic discharge. Aim of our study was the assessment of the diagnostic accuracy of exercise stress test in this condition. To do so, we measured the heart rate at peak stress in 18 patients with sick sinus syndrome (16 men and 2 women aged 51-78 years, mean 68). Two control groups were chosen: one of 14 healthy subjects of the same age and sex and a second one of 19 patients of the same age and sex, with comparable heart disease as the patients under study, but without sinus dysfunction. Heart rate at peak stress was expressed as percent of the expected maximal sex--and age--corrected heart rate (% max HR). The sick sinus syndrome group was characterized by the presence of: syncope and/or near-syncope in 10 patients; slight (2), moderate (9), severe (7) sinus bradycardia; corrected sinus node recovery time longer than 500 msec in 7 out of 15 patients, detected during an electrophysiological study; abnormal intrinsic heart rate in 5 out of 11 patients, obtained by means of drug-induced autonomic blockade (metoprolol 0,2 mg/Kg i.v. and atropine 0,04 mg/Kg i.v.), and evaluated according to Jose's equation; abnormal intrinsic corrected recovery time (greater than 450 msec) in 8 out of 11 patients; increase in heart rate after atropine infusion (0,02 mg/Kg i.v.) of less than 90 beats/min in 15 out of 18 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Chromatin structure of histone genes in sea urchin sperms and embryos

The nucleosomal organization of active and repressed alpha subtype histone genes has been investigated by micrococcal nuclease digestion of P. lividus sperm, 32-64 cell embryo and mesenchyme blastula nuclei, followed by hybridization with 32P-labeled specific DNA probes. In sperms, fully repressed histone genes are regularly folded in nucleosomes, and exhibit a greater resistance to micrococcal nuclease cleavage than bulk chromatin. In contrast, both coding and spacer alpha subtype histone DNA sequences acquire an altered conformation in nuclei from early cleavage stage embryos, i.e., when these genes are maximally expressed. Switching off of the alpha subtype histone genes, in mesenchyme blastulae, restores the typical nucleosomal organization on this chromatin region. As probed by hybridization to D.melanogaster actin cDNA, actin genes retain a regular nucleosomal structure in all the investigated stages.

[The value of tomodensitometry in the diagnosis of dermoid cysts. Apropos of 5 cases]

Results of computed tomography before operation in 5 cases of dermoid cysts (mediastinal: 3; retroperitoneal: 1; ovarian: 1) are employed to assess the contribution of this technique, and to define its place in relation to other diagnostic radiological procedures (straight radiographs and ultrasonography). The CT scan enables three morphological types to be distinguished, and also supplies very precise data on the extension, limits, and relationships of the tumor. The effective place of this examination in the diagnosis of dermoid cysts depends upon two factors: data obtained from the straight radiograph and the initial site of the lesion. When the former supplies specific information, the only role of the CT scan and ultrasonography is to determine the precise extent of the tumor pre-operatively, the CT scan being superior to ultrasonography for this purpose. When straight radiographs do not reveal characteristic signs, the diagnostic assistance of the scanner appears to be irreplaceable, even in those abdominal or pelvic regions where ultrasonography is best conducted.

Transcription of sea-urchin mesenchyme blastula histone genes after heat shock

Mesenchyme blastula sea-urchin embryos were heat-shocked at 31 degrees C and pulse-labelled with [3H]uridine. The nuclear RNA was fractionated on glyoxal/agarose gels and each RNA fraction hybridized with cloned early blastula histone DNA. The results showed that after heat shock there is an accumulation of histone RNA molecules larger than the messenger and a decrease, with respect to the control, of 9-S histone RNA. Chasing of the heat shock RNA by incubation of the embryos with unlabelled uridine and cytidine restores the radioactivity, as well as the hybridization profiles, of control embryos. Furthermore saturation curves obtained by hybridizing histone DNA with labelled 9-S RNA, showed an absence of the histone messenger in the cytoplasm of heat-shocked embryos, whereas it is present in both control and chased embryos. These results are consistent with the hypothesis that the accumulated histone RNA in heat-shocked embryos is the precursor of mature messengers.

[Ultrasonographic guidance of percutaneous biopsies and punctures]

Real time ultrasonography is routinely used for guidance of percutaneous punctures towards small targets, with three goals: 1. Aspiration biopsies for analysis of an abnormality detected with ultrasonography. 2. Injection of contrast media inside normal structures (urinary, biliary or pancreatic tract) or abnormal collection (cysts, pseudocysts). 3. Treatment by percutaneous sclerosis, aspiration, decompression, drainage.

[Suprapubic prostatic ultrasonography (author's transl)]

Suprapubic ultrasonography is now routinely used for prostatic examination as it is simple, non-invasive and accurate. Differential diagnosis between benign hypertrophy and cancer is often possible. Evaluation of the size of the prostate is accurate and is a satisfactory means of monitoring the effect of treatment for prostatic cancer.

[Percutaneous puncture under sectorial real time ultrasonography control]

A technique for percutaneous puncture is described which employs sectorial scanning real time ultrasonography without a mechanical system for needle control. The method has given satisfactory results in 200 punctures, including one case in which a liver metastasis 13 mm in diameter was detected and another case with a wirsung's duct of 4 mm diameter.

[Radiologist-pattern interaction in the processing of fluoroscopic images]

The great complexity of interactions among radiologist, patient and radiological apparatus, when performing radiological tests, is perhaps the main cause of difficulties in the development of automatic systems, both for classification and quantification of radiological images, and for documentation and retrieval of radiological images. The result of such interactions is not a "plate", but a diagnosis, very often the "plate" does not even coincide with the radiological investigation, if this term implies a linkage with the perceptual mechanisms of the radiologist. In other words, the "plate" provides the radiologist with the elements to achieve an interpretation of the image, which will then lead to the diagnosis. In view of a foreseeable spreading of economical medical informatics methodologies, an aim of the present work is stressing the importance of the interactions between medical operators and information processing systems, to select relevant parameters for diagnosis. Sequences of images (originally taken by a movie camera) are presented, which relate to the motor activity of digestive apparatus segments. Processing stresses some of their morpho-dynamic features.

Evidences of two different sets of histone genes active during embryogenesis of the sea urchin Paracentrotus lividus

Histone mRNAs at different stages of development were purified by hybridization with the cloned homologous histone genes. The electrophoretic patterns of oocytes, 2-4 blastomeres, 64 cells and morula histone mRNAs was found to be identical, whereas the electrophoretic pattern of mesenchyme blastula histone mRNA was markedly different. The cloned histone DNA of P.lividus was hybridized with the RNA of each stage. The Tm was 74 degrees C in all cases except for the mesenchyme histone mRNAs whose Tm was 59 degrees C, thus suggesting that at least two different clusters of histone genes are active in the course of the sea urchin development.

Synthesis of histone messenger RNA of HeLa cells during the cell cycle

Hybridization of HeLa cell RNA to the DNA of a recombinant phage containing sea urchin histone genes shows that histone mRNA of HeLa cells is synthesized throughout the entire cell cycle. Furthermore, histone messenger is synthesized in cells treated with cytosine arabinoside, an inhibitor of DNA duplication. Although histone RNA is found in the nucleus, the amount of cytoplasmic histone messenger is drastically reduced, in agreement with previous work. The absence of coupling between histone mRNA synthesis and DNA duplication shows that the regulatory process which determines the presence or absence of histone mRNA in the cytoplasm of HeLa cells is not at the transcriptional level.

Presence of histone mRNA sequences in high molecular weight RNA of HeLa cells

Pulse-labeled HeLa cell RNA centrifuged under denaturing conditions was hybridized with DNA of recombinant phages containing sea urchin histone genes. This cross-hybridization showed the presence of histone mRNA sequences in high molecular weight RNA molecules. Treatment of the cells with actinomycin to stop RNA synthesis resulted in the rapid decay of this high molecular weight RNA followed by an increase of 9S histone mRNA in the cytoplasm. The results are consistent with the presence in HeLa cells of a high molecular weight precursor to histone messengers.

The RNA of unfertilized sea urchin eggs is "capped"

It is shown that the RNA of unfertilized sea urchin eggs is active in stimulating protein synthesis in a wheat germ cell free system. This activity is not lowered by conditions that inhibit the methylation processes but is inhibited by a treatment that damages the "cap", A difference in activity in a wheat germ cell free system between the RNA of unfertilized eggs and the RNA from early embryos is described.