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I Nieto

Publications and source records attributed to I Nieto.

10 recordsLinked to original sources

Stereospecific synthesis of alpha- and beta-C-glycosides from glycosyl sulfoxides: scope and limitations.

C-Glycosides derived from alpha-L-fuco-, alpha-D-gluco-, beta-D-gluco-, and alpha-D-mannopyranose have been synthesized from the corresponding glycosyl phenyl sulfoxide through phenylsulfinyl-lithium exchange, to generate an anomeric carbanion, and subsequent reaction with a carbon electrophile. The reactions were stereospecific and proceeded with retention of the configuration at the anomeric center. Improved yields of C-glycosides were obtained by an inverse addition protocol. Trapping of the anomeric carbanion with aldehydes gave best results. Reaction with ketones, chloroformates, nitriles, and alkyl halides was also explored. Mechanistic aspects of the reaction are discussed.

Glycosides↗

Spasmolytic effect of acidic fibroblast growth factor in early cerebral vasospasm in the rat.

BACKGROUND: In animal models of subarachnoid hemorrhage (SAH), basilar artery spasm has been described. Since fibroblast growth factors (FGFs) dilate rat basilar artery in vivo, we tested whether systemic administration of acidic fibroblast growth factor (aFGF) can reverse the basilar artery spasm following rat SAH. METHODS: SAH was mimicked by injecting autologous blood into the cisterna magna. We used a digital substraction angiography system in order to evaluate the spasmolytic effect of aFGF administered via the axillary artery 7 minutes after the injection of the autologous blood. Control animals received vehicle solution in the same manner. RESULTS: Intraarterial bolus injection of 2.6 micrograms aFGF, but not the solvent, reverses the acute basilar artery narrowing caused by SAH (23.05% of the baseline value at 5 minutes post-SAH). CONCLUSIONS: Our results suggest an important role for FGFs in the cerebral tone regulation and support a clinical interest of FGFs in preventing cerebral ischemia following SAH, particularly if these vasoactive effects are added to the known neuroprotective effects of FGFs.

Angiography, Digital Subtraction↗

Giant molluscum contagiosum in AIDS.

A 31-year-old man, an intravenous drug user and in an advanced stage of acquired immune deficiency syndrome (AIDS), was admitted in our Department for the treatment of skin lesions that had been diagnosed as molluscum contagiosum (MC). The clinical examination revealed the presence of multiple nodular lesions, some of which were notably large and whose color resembled that of normal skin. These lesions were localized mainly to the face, and in particular on the forehead, glabellar, malar, beard, submandibular, and neck regions (Fig. 1). Smaller, crateriform lesions were detected on the hands and the upper limbs. The lymphocyte subsets ratio was 0.02, with a CD4+ T cell count of 13 cells per mm3 (1%) and a CD8+ T cell count of 624 per mm3 (48%). The patient also had leukopenia (1690 WBC per mm3), moderate macrocytic anemia, elevation of transaminases (SGOT 105 U/L, SGPT 114 U/L) and of immunoglobulins (IgG 2660 mg/dL), and a decrease of C3 (44.2 mg/dL) and C4 (16.6 mg/dL). Histologic examination revealed the presence of typical MC lesions. In addition to an important acanthosis, it was possible to detect pyriform lobules of perfectly delineated epidermal cells, radially separated by fibrous septa that merge towards the central crater. The characteristic MC eosinophil bodies were observed in infected cells (Fig. 2). The lesions were treated with cryosurgery by spray. Many courses of therapy were given with intervals of 2-3 weeks. Every session consisted of two cycles of rapid freezing followed by a slow thaw. Many lesions disappeared with this treatment, and others were reduced in size, but total destruction of all lesions was not achieved (Fig. 3).

AIDS-Related Opportunistic Infections↗

[Endoscopic gastrointestinal findings in patients with human immunodeficiency virus infection].

From January 1992 to August 1993, 150 endoscopies (114 fiber gastroscopies, 29 fiber colonoscopies and 7 CPRE) were carried out in a total of 142 anti HIV positive patients. The most frequent clinical manifestations leading to the exploration were dysphagia, epigastric pain, diarrhea and upper or lower gastrointestinal bleeding. Endoscopic alterations were observed in most of the exploration although specific diagnosis was only achieved in approximately one third of the patients with the most frequent being esophagitis by Candida and CMV (21% and 5%, respectively in the fiber gastroscopies performed). Digestive manifestations were varied in the patients in whom esophagitis by Candida was diagnosed while dysphagia and diarrhea were the symptoms commonly observed in the patients with esophagitis or colitis by CMV. The diagnostic profitability of endoscopy was high in patients presenting dysphagia, diarrhea, gastrointestinal bleeding or in those in whom endoscopy was performed for tumoral staging or to evaluate the possible existence of manifestations secondary to the presence of portal hypertension.

Cholangiopancreatography, Endoscopic Retrograde↗

Hypotensive activity of fibroblast growth factor.

Acidic and basic fibroblast growth factors (FGFs) are members of a family of proteins that are broad-spectrum mitogens, have diverse hormone-like activities, and function in tumorigenesis. FGF's ability to raise the concentration of intracellular calcium ion suggests that FGF could induce the synthesis of endothelium-derived relaxing factor (EDRF) and consequently vasodilation. Systemic administration of FGF decreased arterial blood pressure. This effect was mediated by EDRF and by adenosine triphosphate-sensitive potassium ion channels. The hypotensive effect of FGF was segregated from its mitogenic activity by protein engineering. These results extend the range of FGF autocrine activities and potential therapeutic applications, emphasize the role of endothelium as an arterial blood pressure--regulating organ, and provide insight on the structural basis of FGF functions.

Animals↗

[Vascular pathology of the temporal bone].

In a review of our cases over the last twenty years a series of patients from the E.N.T. clinic has been selected, all of which exhibit a clinical history of tinnitus and vertigo, and in some cases hearing loss. Neuroradiological exploration was able to show that a vascular aetiology was responsible in every case. In the literature concerning this type of otological pathology these procedures are seldom found. This study presents our cases and draws attention to the high risk which surgical intervention entails if there is an undiagnosed vascular mass in the middle ear.

Angiography↗

Endoscopic sclerotherapy to arrest uncontrolled variceal bleeding in cirrhotic patients with high surgical risk.

BACKGROUND/AIMS: In 20-50% of patients bleeding from esophageal varices, conservative procedures fail to obtain hemostasis and prevent early recurrence. METHODOLOGY: We retrospectively analyzed the efficacy and safety of endoscopic sclerotherapy in 66 cirrhotic patients with high surgical risk and persistence or recurrence of variceal bleeding in spite of adequate medical treatment (somatostatin and/or balloon tamponade). RESULTS: Emergency sclerosis controlled bleeding in 46 out of 66 patients (70%). The remaining 20 patients underwent additional procedures to arrest the hemorrhage, and 6 died because of massive bleeding. Early rebleeding occurred in 5 patients (10%). The mortality within 2 days, 1 week, and 6 weeks was 9%, 17% and 32%, respectively. Death was attributed to hemorrhage in 9 cases. Sclerotherapy was associated with complications in 9 patients (14%). CONCLUSION: These results suggest that emergency sclerotherapy is a safe and effective procedure in cirrhotic patients with high surgical risk and persistence or recurrence of bleeding after conservative hemostatic procedures.

Adult↗