Biomedical subjects
Publications and source records attributed to G Romeo.
Two partial-length cDNAs encoding the type 1 human hexokinase (ATP:D-hexose 6-phosphotransferase) were isolated from a placenta cDNA library using a 50-bp oligonucleotide synthesized according to the known sequence of human HK1. Using the larger (1.8 kb) cDNA insert as a probe and a panel of human-hamster somatic cell hybrids, we were able to assign the HK1 gene to the long arm of chromosome 10.
The possibility of a relation between high myopia and lens opacity was studied. For this research, the Lens Opacity Meter 701 was used. The lens opacity values measured in 91 high-myopic eyes were compared with those measured in a control group of 106 emmetropic eyes. This comparison showed that myopic had always higher lens opacity values than emmetropic ones, and this result was statistically significant after the age of 20.
Linkage relationships between DNA polymorphism metH/TaqI as well as KM19/PstI and the mutation causing cystic fibrosis (CF) were analyzed in 48 families from Slovakia with th occurrence of CF. The polymorphism metH/TaqI did not show linkage disequilibrium with CF mutation. A pronounced allelic association was however found between CF mutation and KM19/PstI polymorphism. Of the 83 CF chromosomes analyzed, the given mutation was associated with the 6.6 kb allele in 82% of cases, while the rate of this allele in chromosomes without the mutation amounts only to 24%. The value of the standardized disequilibrium coefficient SCD = 0.58. Delta F508 deletion was addressly studied in 25 patients (i.e. 50 CF chromosomes). Of the 50 CF mutations, the given deletion was in 64% (32), while the remaining 36% (18) of mutations were of other, closely not identified types. Delta F508 deletion is in marked allelic association with the 6.6 kb allele of KM19/PstI polymorphism (SCD = 0.68). Between the given allele of KM19/PstI polymorphism and CF mutation no other allelic association was found but with delta F508. (Tab. 6, Fig. 1, Ref. 18).
Over a 2-year period (1989-90), about 400 cases were examined (out of nearly 2,500 US examinations of the prostate), 244 of which had subsequent bioptic, surgical or autoptic confirmation. This paper reports the anatomic, clinical and pathologic data relative to the seminal vesicles of 244 subjects who underwent transrectal US of the prostate for different clinical indications. Our biometric values were slightly different from those reported in literature, the latter being based on autoptic findings. Agenesis and monolateral ectopia were confirmed to be extremely rare: 4 cases only (1.6%) in our series. A typical finding was the nearly perfect symmetry; in size and structure, of the two seminal vesicles in the same subject; as a matter of fact, a loco-regional pathologic condition was detected in all the patients (14) with asymmetry. A hundred per cent agreement was observed between the US patterns of the seminal vesicles and the prostatic patterns in case of acute/subacute prostatic inflammation involving also the 2 glands: this parameter can be used to follow the clinical course of the inflammatory process.
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The effect of succinylacetone (SA), a highly specific inhibitor of ALA-dehydratase and heme synthesis, on hemoglobin (Hb) production, transferrin receptor (TfR), and ferritin expression was analyzed in differentiating Friend leukemia cells (FLC). This compound exerted a pronounced inhibitory effect not only on heme and Hb synthesis, but also on all the remaining above-mentioned parameters. In particular, SA induced: (1) a reduction of the level of alpha-globin mRNA; (2) a decreased number of exposed TfR molecules, without modification of their affinity for the ligand; (3) a reduced level of TfR RNA, without significant change of TfR gene transcription rate; and (4) a lower ferritin content. The addition of exogenous hemin to differentiating FLC exerted opposite effects, and particularly induced an increase of both the number of TfRs and ferritin content. These findings suggest that in erythroid cells optimal heme synthesis is required to coordinately sustain globin chains synthesis and TfR/ferritin production; thus, the intracellular heme level may represent a key regulatory factor in the Hb synthesis pathway.
A voltage-dependent K+ current has been revealed in whole-cell recordings carried out on immortalized cells obtained from the human tracheal epithelium. At positive membrane potentials the current shows a time dependent inactivation which is accelerated by increasing the depolarizing step. Forskolin, a direct activator of adenylyl cyclase, and verapamil, a Ca2+ channel blocker, induce the K+ current to inactivate more rapidly. Control experiments show that the action of these two compounds is not mediated by cyclic AMP and Ca2+. The application of 1,9-dideoxyforskolin, an analogue which does not stimulate adenylate cyclase, inhibits the current in the same way as forskolin; on the contrary, the dibutyryl analogue of cyclic AMP is ineffective. Furthermore, eliminating extracellular Ca2+ does not affect K+ current kinetics. Tetraethylammonium is an effective blocker of this current with an IC50 of 0.3 mM.
The intraoperative esophageal manometry (IEM) has been used to improve results in operative management of gastroesophageal reflux and achalasia. The IEM pointed out the necessity to perform an antireflux procedure with an intraoperative sphincter pressure higher than normal, because the measured postoperative sphincter pressures were one-half the intraoperative values measured after repair. Nevertheless some authors failed to find any correlation between intraoperative and subsequent postoperative sphincter pressure measurements. The Authors, in their experience, achieved the same results with and without IEM in the surgical management of gastroesophageal reflux and achalasia. For this reason The IEM does not seem to be necessary when performing the standard Nissen or Heller procedure. It is probably useful in the surgical treatment of patients with motor disorders or sclerodermia associated with reflux and in patients who have had multiple prior operations for reflux or achalasia.
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Administration of highly purified preparations of murine interferon (IFN)-alpha 1, -alpha 4, -alpha 6, or -beta to Friend leukemia cells induced to differentiate by dimethyl sulfoxide leads to a 100% increase of benzidine-positive (B+) cells. Different efficiencies for the two IFN species have been observed; a 10-fold higher dose of IFN-alpha is needed for stimulation of hemoglobin production and inhibition of cell growth as compared with IFN-beta. Both species of IFN induce a substantial increase in heme, hemoglobin, and transferrin receptor levels. In vitro run-on transcription assays indicate that IFN-beta moderately stimulates transcription of the alpha-globin gene but not the transferrin receptor gene. It is postulated that IFN induces the enhancing effect on differentiation via a marked increase of heme synthesis and number of transferrin receptors, which in turn leads to an enhancement of globin chain synthesis. In this regard, the negative feedback reported in a variety of other cell types for the regulation of transferrin receptor expression by heme does not seem to be operative in maturing Friend erythroleukemia cells, which present evidence for a positive mechanism.
Fucosidosis is a rare, autosomal recessive, lysosomal storage disorder caused by a severe deficiency of alpha-L-fucosidase in all tissues. We have conducted a review of fucosidosis, compiling data from published reports and an international questionnaire survey. Seventy-seven patients affected with fucosidosis of which 19 had not been reported before have been identified. A major aim of the present study was to define the natural history of fucosidosis. The clinical picture of fucosidosis consists of progressive mental (95%) and motor (87%) deterioration, coarse facies (79%), growth retardation (78%), recurrent infections (78%), dysostosis multiplex (58%), angiokeratoma corporis diffusum (52%), visceromegaly (44%), and seizures (38%). Whereas the original fucosidosis patients described by Durand et al. (J. Pediatr 75:665-674, 1969) were decerebrate and died before age 5 years, most fucosidosis patients have a slower course of degeneration. Mortality before age 5 years was observed in only 7 patients (9%), whereas 36 patients (64%) reached the second decade. We did not find evidence for the existence of clinical heterogeneity with a rapidly progressive type I and a slowly progressive type II fucosidosis as suggested in the literature. Instead, there seems to exist a wide continuous clinical spectrum. At the biochemical level no heterogeneity in residual fucosidase enzyme activity or cross-reacting immunoreactive fucosidase protein was observed. At the DNA level at least 4 different mutations must be responsible for fucosidosis. These genotypic differences however do not explain the observed phenotypic differences.
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The molecular analysis of 127 DMD/BMD patients showed that 73 of them (57%) had deletions in the dystrophin gene. Two different methods were used in this study: (a) hybridization of HindIII-digested genomic DNA with nine cDNA probes corresponding to the entire 14kb cDNA of the DMD gene; and (b) simultaneous amplification of nine exons of the DMD gene (multiplex DNA amplification) by the polymerase chain reaction (PCR). When the deletion breakpoints of the intragenic deletions were analyzed with regard to their phenotypic consequences, nine patients were found to represent exceptions to the reading-frame hypothesis. Information regarding mental development was also available for 61 of the 73 deleted patients and for 34 of the 54 non-deleted ones. The proportion of mentally retarded patients was found to be similar in the two groups (deleted, 15%; non-deleted, 18%). Finally, in one family, a junction fragment present in the patient was not found in the peripheral blood DNA of the mother but was present in the sister, thus indicating germline mosaicism in the mother.
The hypothesis of germinal mosaicism in the unaffected mother of two half-sisters affected with Rett syndrome is postulated to explain the unusual recurrence of this genetic disorder affecting only females (1/10,000); it might be caused by new X-linked mutations with lethality in male fetuses. The analysis of 34 X-linked restriction fragment length polymorphisms (RFLPs) in these two affected females and in their unaffected mother and half-brother, together with the reconstruction of phase for 15 informative RFLPs in somatic cell hybrids retaining a single X chromosome from each female, has made it possible to exclude some regions of the X chromosome as possible sites of the mutation(s) causing Rett syndrome.
Tenascin (TN) is a hexameric extracellular matrix glycoprotein that is highly expressed in solid tumors but has a restricted distribution in normal adult tissues. Each TN subunit is composed of segments with high homology to the sequences of epidermal growth factor, fibronectin and fibrinogen. Furthermore, it has been suggested that TN could modulate epithelial-mesenchymal and neuronal-glial interactions. Here, using a cDNA probe to human TN, we have carried out Southern blot analysis of the genomic DNAs from a panel of human-hamster somatic cell hybrids carrying different complements of human chromosomes. The results demonstrate that the human TN gene is located on chromosome 9. Furthermore, in situ hybridization studies demonstrate that human TN is located at 9q32-q34.