Biomedical subjects
Publications and source records attributed to F Ciani.
We report on a neonate with hyperammonemic coma in whom hyperornithinemia-hyperammonemia-homocitrullinuria syndrome was diagnosed. Appropriate treatment led to rapid clinical and metabolic improvement. The incorporation of 14C-ornithine on cultured fibroblasts confirmed the diagnosis. At the age of 18 months, the patient is in excellent clinical condition.
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The molecular characterization of glial lineage cells in two urodele species, Ambystoma mexicanum and Triturus carnifex, has been investigated immunocytochemically with antibodies directed against intermediate filament proteins, glial fibrillary acidic protein (GFAP) and vimentin. Ambystoma astroglia shows clear GFAP-immunopositivity and vimentin-immunonegativity. The condition in Triturus is quite the opposite, showing only a strong vimentin immuno-reaction. In these urodele brain the astroglia is represented by radial glial cells with their somata lining cerebral ventricles (tanycytes). Each of them originates a thick process which radially crosses the periventricular gray matter and branches within the neuropil. These glial fibers originate endfeet on the subpial surface and on blood vessel wall. Only in the spinal cord cell bodies of immunopositive radial glia are displaced from the ependyma of the central canal which is almost immunonegative except the tanycytes forming the dorsal and ventral septum. No mammalian-like astrocytes appear neither in brain nor in spinal cord. The interspecific difference in the intermediate filament protein expression in radial glial cells could suggest that as regards this character Triturus retains a more immature condition than Ambystoma.
Lectin binding histochemistry was performed on the olfactory system of Pseudemys scripta to investigate the distribution and density of defined carbohydrate terminals on the cell surface glycoproteins of the olfactory receptors and their terminals in the olfactory bulbs. The lectin staining patterns indicate that the receptor cells of the olfactory mucosa are characterized by glycoconjugates containing alpha-D-galactose and N-acetyl-D-glucosamine terminal residues. The vomeronasal receptor cells contain instead alpha-N-acetyl-D-galactosamine, N-acetyl-D-glucosamine and alpha-D-galactose residues. The results demonstrate that the vomeronasal receptor cells contain high density of alpha-N-acetyl-D-galactosamine sugar residues that are not expressed by receptor cells of the olfactory mucosa. The presence of specific glycoproteins, whose terminal sugars are detected by lectin binding, might be related to the chemoreception and transduction of the odorous message into a nervous signal or in the histogenesis of the olfactory system. In fact, the olfactory receptors are the only known neurons in the vertebrate nervous system that undergo a continual cycle of proliferation not only in developing animals but also in mature ones. Moreover the results show that BSA-I-B4, an alpha-D-galactosyl-specific isolectin, targets the terminal sugar residues in the ramified microglial cells.
The aim of this study was to evaluate whether long-term glucose control, as assessed by fasting plasma glucose determinations during 3 years, is a predictor of all-cause mortality in elderly NIDDM patients. Five hundred and sixty-six NIDDM patients attending the Verona Diabetes Clinic, aged 75 years and over, were followed-up from 1 January 1987 to 31 December 1991 to assess all-cause mortality. From their clinical records all fasting plasma glucose determinations available for the years 1984 to 1986 were collected and analysed. Patients were grouped in tertiles according to mean (M-FPG), coefficient of variation (CV-FPG) and trend over time (slope, S-FPG) of fasting plasma glucose during the period of retrospective evaluation. Mortality was assessed by observed/expected ratios, univariate Kaplan-Meier survival analysis and multivariate Poisson regression model. By 31 December 1991, 61 men and 127 women had died. Increased observed/expected ratios were found in women from the top M-FPG tertile, in patients (men and women) from the top CV-FPG tertile and in patients with a S-FPG less than -0.30 mmol/l per year (lowest tertile). Patients in the lowest tertile of CV-FPG and in the middle tertile of S-FPG had a reduced mortality risk. Kaplan-Meier survival analysis indicated that patients with high CV-FPG as well as those in tertiles I and III of S-FPG (i.e., those with a definitely negative or definitely positive slope) had an increased probability of dying, without any significant differences between the three tertiles of M-FPG.(ABSTRACT TRUNCATED AT 250 WORDS)
We report on a patient with transient nonketotic hyperglycinemia (NKH). Onset, clinical features, biochemical and electroencephalographic findings were consistent with neonatal nonketotic hyperglycinemia. The normalization of clinical, biochemical and electroencephalographic features on day 9 without specific therapy suggested a transient form. At the last follow-up the girl was 13 years old, had a normal mental development, no EEG abnormalities or neurological deficits.
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The loop of Henle (LOH) reabsorbs approximately 15% of filtered HCO3- via a luminal Na(+)-H+ exchanger and H+ATPase. During acute metabolic alkalosis (AMA) induced by i.v. HCO3- infusion, we have observed previously inhibition of LOH net HCO3- reabsorption (JHCO3-), which contributes to urinary elimination of the HCO3- load and correction of the systemic alkalosis. To determine whether the activities of the Na(+)-H+ exchanger and/or H(+)-ATPase are reduced during AMA, two inhibitors believed to be sufficiently specific for each transporter were delivered by in vivo LOH microperfusion during AMA. AMA reduced LOH JHCO3- from 205.0 +/- 10.8 to 96.2 +/- 11.8 pmol.min-1 (P < 0.001). Luminal perfusion with bafilomycin A1 (10(-4) mol.l-1) caused a further reduction in JHCO3- by 83% and ethylisopropylamiloride (EIPA; 5.10(-4) mol.l-1) completely abolished net HCO3- reabsorption. The combination of bafilomycin A1 and EIPA in the luminal perfusate was additive, resulting in net HCO3- secretion (-66.6 +/- 20.8 pmol.min-1; P < 0.001) and abolished net fluid reabsorption (from 5.0 +/- 0.6 during AMA to 0.2 +/- 1.1 nl.min-1; P < 0.001). To establish whether HCO3- secretion via luminal stilbene-sensitive transport mechanism participates in LOH adaptation to AMA, we added diisothiocyanato-2,2'-stilbenedisulphonate (DIDS; 10(-4) mol.l-1) to the perfusate. No effect was found.(ABSTRACT TRUNCATED AT 250 WORDS)
Lectin-binding histochemistry was used to investigate the distribution and density of defined carbohydrate sequences on the cell surface glycoproteins of the olfactory receptors of rat during development. The olfactory and vomeronasal receptors showed a positive labelling after biotinylated Lycopersicum esculentum lectin binding on embryonic day 16 (E16), while horseradish peroxidase-labelled Glycine max, Bandeiraea simplicifolia (BSA-I) and its B4 isomer BSA-I-B4 agglutinins started to label from day 18 (E18). From this stage onward there was a progressive increase in the intensity and number of lectin-binding olfactory receptors. The first lectin-labelled bundles of axons penetrating the olfactory bulb were observed on E20; from E21 it was possible to identify the first labelled glomeruli that, on the first day (P1) of postnatal life, showed a feature very similar to that of the adult. The lectin staining patterns indicate that during development there are differences in the kind and distribution of saccharidic moieties on the surface of rat olfactory neurons. The possible role of carbohydrate-containing glycoproteins in the reception and transduction of the odours and in the modulation of the cell-cell interactions in the olfactory system is discussed.
We report an infant with neonatal nonketotic hyperglycinemia (NKH), diagnosed early and treated with dextromethorphan (DM) and sodium benzoate therapy from the 65th hour of life. Initially the patient responded to treatment showing clinical and electroencephalographic improvement: myoclonic jerks disappeared, muscular tone, reactivity to stimuli and spontaneous movements increased, assisted ventilation was no longer necessary and bottle feeding was initiated successfully; on EEG the suppression-burst pattern disappeared and the background activity was well-organized. At three months of age he developed flexor spasms and hypsarrhythmia. In spite of increasing doses of DM as high as 40 mg/kg/day and persistent therapy with sodium benzoate the child progressively deteriorated and died at the age of 5 months and 7 days. We stress that the adverse clinical course occurred in our patient even though DM and sodium benzoate therapy was started much earlier than in other reported cases. It is possible that prenatal brain damage and probable genetic variants (i.e. absent or minimal residual enzymatic activity and interindividual variations in DM metabolism) affect the response to therapy.
The loop of Henle contributes to renal acidification by reabsorbing about 15% of filtered bicarbonate. To study the effects on loop of Henle bicarbonate transport (JHCO3) of acid-base disturbances and of several factors known to modulate sodium transport, these in vivo microperfusion studies were carried out in rats during: (a) acute and chronic metabolic acidosis, (b) acute and chronic (hypokalemic) metabolic alkalosis, (c) a control sodium diet, (d) a high-sodium diet, (e) angiotensin II (AII) intravenous infusion, (f) simultaneously intravenous infusion of both AII and the AT1 receptor antagonist DuP 753, (g) acute ipsilateral mechanicochemical renal denervation. Acute and chronic metabolic acidosis increased JHCO3; acute metabolic alkalosis significantly reduced JHCO3, whereas chronic hypokalemic alkalosis did not alter JHCO3. Bicarbonate transport increased in animals on a high-sodium intake and following AII administration, and the latter was inhibited by the AII (AT1) receptor antagonist DuP 753; acute renal denervation lowered bicarbonate transport. These data indicate that bicarbonate reabsorption along the loop of Henle in vivo is closely linked to systemic acid-base status and to several factors known to modulate sodium transport.
The corrosion cast technique provided for the first time an excellent three-dimensional visualization of the vascular pattern of the choroid and iris in the newt eye. The results show the presence of a single arterial afference to the choroidal and iris capillaries: the ophthalmic artery is the origin of both ciliary arteries and the long posterior ciliary artery. Slightly behind the equatorial circumference of the eyeball the venous drainage consists of a single vessel on the dorsal side and two distinct vessels on the ventral one. It receives blood from both iris and choroid. The surface of the plastic endocasts shows some details of fine luminal structures of the endothelial cells. Shallow depressions may be regarded as imprints of endothelial cell nuclei, and they are distinctly different for arteries and capillaries. The angioarchitecture of the newt eye differs from that of brain in that hairpin-shaped capillary loops are not observed at all.
The binding of 14 lectins were performed on paraffin-embedded sections of the olfactory bulb of Triturus to identify specific glycoconjugates on the cell surface of primary olfactory projections. The histochemical lectin staining patterns indicate that the membrane of olfactory neurons terminating in the main olfactory bulb contained prevalently oligosaccharides with alpha-acetyl-D-galactosamine as terminal residues. In the accessory olfactory bulb, instead, the primary olfactory projections possess a high density of alpha-D-galactose as sugar residues. The selective lectin binding on the surface of primary olfactory axons suggests that specific cell surface glycoproteins may have a role in the axonal growth due to the continual cycle of proliferation and death of olfactory receptors.
Lectin histochemical studies were performed on the olfactory system of Scyliorhinus canicula to identify specific glycoconjugates on the cell surface of primary olfactory neurons. The olfactory receptor cells, the olfactory nerve fibers and their terminals in the bulbs were labelled with SBA, BSA-I and BSA-I-B4. The lectin staining patterns indicate that the membranes of small-spotted catshark olfactory neurons had glycoproteins with alpha-galactose residues. This carbohydrate moiety could be related to modulation of the cell-cell interactions in the olfactory system.
Seven biotinylated lectins were utilized as histochemical markers for the study of microglial cells in the brain of Salamandra salamandra. It has been demonstrated that SBA, BSA-I, BSA-I-B4 and RCA120 label the microglial cells and, on the basis of the binding selectivity of the single lectins for specific carbohydrates, it was found that alpha-galactosyl residues are present in high density on the microglial membrane of S. salamandra. The reaction was localized not only to the ramified microglial cells, but also to other round cells without extensions, interpreted as ameboid microglial cells. The results show that lectin binding is a reliable molecular probe for identifying microglial cells in urodels.
The uptake of 6-H3 thymidine in the optic tectum and the forebrain of the newt following injury to one of the two nervous areas, shows a marked proliferative response in the telencephalon in the presence of a lesion on the right optic tectum, and a poor response of the optic tectum after a lesion on the right telencephalic lobe. A similar proliferative response is also obtained when the specimens received only the cold shock. In both experimental conditions maximum uptake is obtained after 7 days. It is assumed that the matrix cells of the forebrain and the undifferentiated cells of the optic tectum respond differently to the regeneration factor released by the nervous tissue following a lesion or a cold shock.
Ambystoma and Xenopus were used to investigate olfactory terminations in the forebrain by exploiting the selective binding of soybean agglutinin to primary olfactory projections. Lectin binding and tridimensional reconstruction provided new information on the distribution of olfactory glomeruli and on regional and interspecific differences. Ambystoma showed an uniform labelling of all olfactory terminations, which were localized in the rostro-lateral forebrain without obvious segregation of different terminal fields, except at dorsal levels. On the contrary, the binding pattern of Xenopus confirmed the existence of three sets of primary olfactory neurons characterized by clear differences in lectin binding. Selective soybean agglutinin binding and a detailed tridimensional reconstruction provided evidence for the existence of a set of neuronal projections, described for the first time, which terminate in a discrete bilateral region of the forebrain localized below the main olfactory bulb. The presence of three different sets of primary olfactory neurons, the experimental potentials and the possible functional significance of SBA binding sites are discussed.