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Biomedical subjects

R Capasso

Publications and source records attributed to R Capasso.

At least 19 recordsLinked to original sources
PubMed1997

Fungitoxic activity of some cytochalasins and their derivatives on Phytophthora species.

The activity of cytochalasin B was tested on 8 Phytophthora species, while the same toxin, some of its derivatives and natural analogues, namely cytochalasin F and deoxaphomin, were assayed at 2 x 10(-5) - 2 x 10(-4) M on the most sensitive species, P. cactorum. A significant inhibitory activity on P. cactorum was shown by cytochalasin B, its 7-monoacetyl derivative, and deoxaphomin. The hydroxy group at C-20 and the conformational freedom of the macrocyclic ring proved to be important structural features for this activity. The 7-hydroxy group at C-7 appeared to have no influence on this toxicity, while a size reduction associated with the carbocyclic nature of the macrocycle seems to lightly increase the activity. The 7-O-acetylcytochalasin B showed selective toxic activity on P. cactorum at the tested concentration, thus suggesting a possible use as a fungicide for this compound.

Cytochalasins↗
PubMed1997

Acquired dysgraphia in alphabetic and stenographic handwriting.

We report the unusual case of AZO, who professionally used handwritten shorthand writing, and became dysgraphic after a stroke. AZO suffered from a complex cognitive impairment, and part of her spelling errors resulted from damage to auditory input processing, to phonology-orthography conversion procedures and to the ortographic output lexicon. However, analysis of her writing performance showed that the same variables affected response accuracy in alphabetic and shorthand writing; and, that the same error types, including transpositions, were observed in all tasks in the two types of writing. These observations are consistent with damage to the graphemic buffer. They suggest that, in multiple-code writing systems (e.g., stenography, Japanese, or in the case of multilingual speakers of languages that use different spelling codes), the graphemic buffer is shared by all codes.

Agraphia↗
PubMed1997

Combined vascular injuries and limb fractures.

Blunt arterial injuries secondary to bone fractures are frequently associated with nerve, vein and soft tissue lesions. A delayed diagnosis or treatment is the main cause of high amputation rate. Thirty-four patients presenting acute arterial occlusion (15 cases), false aneurysms (13 cases) or AVFs (6 cases) of the extremity were identified between 1983 and 1995. To repair injured arteries, ligation (3 cases), patch angioplasty (6 cases), autogenous vein (15 patients) or PTFE (4 cases) interposition or bypass grafting were made. Percutaneous embolization by coils was performed in 3 AVFs of small limb arteries. Associated venous lesions were treated in 9 patients. External fixation of long bone fractures was made in 29 patients, before vascular reconstruction, to prevent further injury during orthopedic stabilization. Fasciotomies were made in 6 patients to treat compartmental hypertension. Early reexplorations were necessary to correct technical defects in 4 patients. Hyperbaric oxygen therapy was applied in 7 patients to control bacterial contamination and improve wound healing. Primary (2 cases) or secondary (3 cases) amputations were carried out in unsalvageable limbs. Nerve or extensive muscle damage caused poor functional outcome in 4 patients. A multidisciplinary diagnostic and management strategy is required to improve limb and patient survival.

Adolescent↗
PubMed1997

Intra-abdominal acute diseases simulating rupture of abdominal aortic aneurysms.

OBJECTIVE: To assess preoperative diagnosis of intra-abdominal acute diseases manifesting as a RAAA and determine treatment options. DESIGN: Retrospective review, with a mean follow-up period of 4 years. SETTING: Vascular Department, Medical School, University "Federico II" of Naples, Italy. METHODS: In 12 patients (8.7%) with clinical suggestion of RAAA were found other intra-abdominal acute lesions, associated with asymptomatic aortic aneurysm in 10 of them and absence in one; the remainder had an intact common iliac artery aneurysm. Sonography was performed in the operating room in 5 patients (41.6%) in shock, 4 hemodynamically stable patients (33.3%) had CT scanning or MRI investigations, while 3 (25%) underwent surgery directly. INTERVENTIONS: Three patients were not operated; one half of patients were submitted to emergency laparotomy and in the remaining 3 patients a preoperative preparation was made. Simultaneous aneurysm repair and nonvascular procedures were performed in 4 patients; nonvascular operations alone were carried out in 5 patients. 4 patients underwent a successful later treatment of their aneurysms: two aneurysmectomy and two endoluminal stenting were done within 4 months. RESULTS: Weight loss and fever were found at 58.3% and 50% of patients with concomitant intra-abdominal acute diseases; both were present in 41.6%. Noninvasive imaging techniques detected associate lesions in 6 of 8 patients (75%) and absence of aneurysm in one having a bleeding adrenal mass. There were three in-hospital deaths: one patient died of metastatic disease without operation and two after surgery (22.2%). Two late deaths from cancer cachexia occurred at 11 months and 3.6 years. CONCLUSIONS: Atypical findings, such as weight loss and fever may be suggestive of coincident lesions in patients with suspected RAAA. Noninvasive assessment may identify associated diseases simulating aneurysmal rupture, without a delay in the treatment. A selective policy of medical or operative therapy may be effective to minimize risk of complications and mortality rate.

Abdomen, Acute↗
PubMed1996

Cytochalasin W, a new 24-oxa[14]cytochalasan from Phoma exigua var. heteromorpha.

A further cytochalasin was isolated from liquid culture filtrates of Phoma exigua var. heteromorpha together with cytochalasins U and V and other well-known cytochalasins. The metabolite, named cytochalasin W, was characterized by spectroscopic and chemical methods as a new 24-oxa[14]cytochalasan, bearing a formyl group on the macrocyclic ring. Cytochalasin W showed toxic activity in the brine shrimp assay.

Animals↗
PubMed1996

The treatment of anomia resulting from output lexical damage: analysis of two cases.

This study describes a treatment project, carried out with two anomic subjects, RBO and GMA failed to name pictures correctly as a consequence of damage to phonological lexical forms; their ability to process word meaning was unimpaired. Words that were consistently comprehended correctly, but produced incorrectly by each subject, were identified. Some words were treated, whereas some served as the control set. A significant improvement was observed in both subjects. As predicted by the model of lexical-semantic processing used as the theoretical background for the study, improvement was restricted to treated items and did not generalize to untreated words, not even to words that were semantically related to those administered during treatment. Improvement was long-lasting, as shown by the fact that 17 months post-therapy GMA's performance on treated words was still significantly better than before treatment. These results are discussed in relation to the claim that cognitive models can be profitably used in the treatment of language disorders.

Adult↗
PubMed1996

Visceral artery aneurysms secondary to collateral circulation.

OBJECTIVE: To evaluate dilatation of visceral arteries secondary to anomalies and collateral circulation. DESIGN: Case report. SETTING: Department of Vascular Surgery, University Hospital. PATIENTS: Two patients with secondary visceral aneurysms were reported. First patient (case 1) had a mid-aortic dysplastic syndrome with multiple aneurysms of the celiac trunk and right renal artery. Other patient (- case 2) presented an inferior pancreaticoduodenal artery aneurysm associated with proximal common hepatic artery occlusion. INTERVENTIONS: The case 1 was submitted to aortic and left renal artery angioplasty (PTFEE), while in the case 2 the resection of aneurysm was performed. RESULTS: Both patients had complete resolution of symptoms and are alive today. CONCLUSIONS: Clinical observations confirmed the development of visceral artery aneurysms secondary to arterial hypertension and collateral circulation.

Adult↗
PubMed1996

Toxic metabolites from phytopathogenic Ascochyta species.

We review some chemical and biological aspects of toxic metabolites produced in vitro by phytopathogenic Ascochyta species, fungi having agrarian and toxicological importance. In particular, here the isolation of some known and new cytochalasins from A. heteromorpha and A. lathyri, four new nonenolides from A. pinodes and a new trisubstituted derivative of salycilic aldehyde from A. pisi are described. Furthermore, the identification of medicarpin, phytoalexin found in the chickpea seeds naturally infected by A. rabiei is also reported.

Carbohydrate Sequence↗
PubMed1995

Selective deficit in processing double letters.

This paper reports a patient with a selective difficulty in spelling words and pseudowords with geminate (double) consonants. In all writing tasks, deletions of a geminate consonant occurred ten times more often than deletions of a consonant in a non-geminate cluster. In addition, the probability of substituting both geminate consonants was indistinguishable from the probability of substituting one consonant in a non-geminate cluster; and, the probability of substituting only one geminate consonant was close to zero, and significantly lower than the probability of substituting one consonant in a non-geminate cluster. This pattern of performance is consistent with the hypothesis that grapheme quantity and identity are separately represented in orthographic representations. The fact that these errors occurred in the absence of a significant number of geminate transpositions is interpreted as support for the hypothesis that letter gemination is specified by a "doubling feature."

Adult↗
PubMed1995

Antibacterial polyphenols from olive oil mill waste waters.

Olive oil vegetation waters (VW) were highly toxic to both phytopathogenic Pseudomonas syringae (Smith, Yung et al.) pv. savastanoi (Gram-negative) and Corynebacterium michiganense (Gram-positive) and showed bactericidal activity in their original concentration (in raw form). Among the main polyphenols, present in the waste waters, methylcatechol proved to be the most toxic to Ps. savastanoi at 10(-4) mol l-1, and also demonstrated bactericidal activity, while on Coryne. michiganense it was only slightly active; catechol and hydroxytyrosol were less active on Ps. savastanoi, but inactive on Coryne. michiganense; tyrosol and its synthetic isomers 1,2- and 1,3-tyrosol were completely inactive on both bacteria. Among the derivatives of VW polyphenols considered, acetylcatechol and guaiacol were selectively toxic for Ps. savastanoi, while o-quinone was strongly toxic for both bacteria. The minor carboxylic polyphenols of VW at 10(-4) mol l-1 were all inactive on the bacteria. VW, catechol, 4-methylcatechol and the less abundant carboxylic polyphenols proved to be toxic on Hep2 human cells. Finally the possibility of using the active polyphenols in agriculture in an integrated pest management program for the protection of the olive plant is discussed.

Anti-Bacterial Agents↗
PubMed1994

The interaction of lexical and sublexical processes in reading, writing and repetition.

It has recently been proposed that in the course of repetition, reading aloud and writing to dictation, lexical representations are activated and selected for output by the joint operation of the semantic system and of sublexical conversion mechanisms--the Summation Hypothesis [Hillis and Caramazza, Brain Lang. 40, 106-144, 1991]. The hypothesis predicts that semantic errors in oral reading and in writing to dictation should only occur when both the semantic system and the sublexical component involved in that task (orthography to phonology and phonology to orthography conversion, respectively) are damaged. The performance of Italian patient E.C.A. indicates damage to the semantic system, and to sublexical phonology to phonology and phonology to orthography conversion mechanisms, but with substantial sparing of sublexical orthography to phonology conversion processes. In agreement with expectations derived from the Summation Hypothesis, E.C.A. produced semantic errors in repetition and in writing to dictation, but not in reading aloud. The paucity of semantic errors in speakers of languages with relatively transparent orthographies is discussed in the context of the Summation Hypothesis.

Aged↗
PubMed1992

Fast atom bombardment, electron ionization and chemical ionization mass spectrometry of 1,2,3-benzenetricarboxylic acids, inhibitors of the mitochondrial tricarboxylate carrier.

It has been discovered that 1,2,3-benzenetricarboxylic acid and some 5-substituted derivatives are specific and competitive inhibitors of the mitochondrial tricarboxylate carrier. In order to characterize these acids a study was carried out using electron ionization (EI), chemical ionization (CI) and fast atom bombardment (FAB) mass spectrometry on the free acids, the potassium salt of 1,2,3-benzenetricarboxylic acid and the corresponding methyl esters. Unimolecular decomposition processes were also studied using B/E linked scan experiments in order to correlate peaks present in the FAB mass spectra of the above compounds. The FAB ionization method, as expected, was the most suitable for analysing the very polar and thermolabile acids and the only method which could be used for the analysis of the potassium salt. EI and CI turned out to be appropriate methods for analysing the less polar and thermostable trimethyl esters.

Benzene Derivatives↗
PubMed1991

A crosslinguistic study of grammaticality judgments in Broca's aphasia.

Crosslinguistic studies of sentence comprehension and production in Broca's aphasia have yielded two complementary findings: (1) grammatical morphology appears to be more impaired than word order principles in every language studied, but (2) the degree to which grammatical morphology is retained by aphasic patients depends upon the "strength" or importance of those morphemes in the patient's premorbid language. In an earlier study comparing violations of word order and agreement, we found that English-speaking Broca's aphasics showed greater sensitivity to errors of ordering than to errors of agreement, providing further evidence for the selective vulnerability of morphology. However, because English is a rigid word order language with a relatively weak inflectional system, it could be argued that word order is resilient to brain damage because it is the strongest source of information in this language. The present study compared the performance of English-speaking Broca's aphasics and normal controls with their Italian counterparts in the same grammaticality judgment experiment. Four predictions relating to our previous work were confirmed. (1) Italian aphasics, like their English-speaking counterparts, showed general preservation of grammatical knowledge and (2) they were able to use this knowledge in an "on-line" fashion. (3) Within each language, Broca's aphasics showed greater impairment in their ability to recognize errors of morphological selection (i.e., agreement) compared with errors made by moving the same words to an incorrect position downstream. Nevertheless (4), crosslinguistic differences observed in previous studies of comprehension and production were also observed in this grammaticality judgment task: a processing advantage for agreement errors in Italian normals and aphasics, and a processing advantage for ordering errors in English normals and aphasics.

Adult↗
PubMed1989

Analysis by fast atom bombardment mass spectrometry of 4,4-dicarboxy-5-(pyridoxyl-5'-phosphate)-proline, of 4-carboxy-5-(pyridoxyl-5'-phosphate)-proline and 4,4-dicarboxy-5-pyridoxylproline.

gamma-Carboxyglutamic acid (Gla) reacts easily and quantitatively with piridoxal-5'-phosphate in H2O at room temperature, to give the 4,4-dicarboxy-5-(pyridoxyl-5'-phosphate)-proline (1). This product has been characterized by fast atom bombardment (FAB) mass spectrometry, including the B/E linked scan technique, ultraviolet and 1H nuclear magnetic resonance (NMR) analysis. In order to support further on the structure of 1, the 4-monodecarboxyderivative (2), obtained by heating compound 1 at 100 degrees C for 30 min and the 5'-dephosphoderivative (3), obtained by enzymatic hydrolysis of 1 with alkaline phosphatase, were also analysed by FAB and 1H NMR techniques. FAB was shown to be the only adequate ionization technique to deal with such thermolabile and non-volatile compounds and could provide an elegant and fast method to detect Gla in biological matrices.

Magnetic Resonance Spectroscopy↗
PubMed1979

Identification of the amino acid residues of proteins S5 and S8 adjacent to each other in the 30 S ribosomal subunit of Escherichia coli.

When Escherichia coli 30 S ribosomal subunits are reacted with protein-protein bifunctional reagents, a number of protein pairs as well as aggregates containing three or more ribosomal proteins are formed. In the present study we have purified one of the protein pairs obtained by reaction of 30 S ribosomal subunits with either radioactive or nonradioactive dimethylsuberimidate. Following molecular weight determination and ammonolysis, the pair was shown to consist of ribosomal proteins S5 and S8. The "native" structure of the complex was surmised from its capacity to be reconstituted into a biologically active 30 S ribosomal subunit. From peptide maps and primary structure determination of various peptides it was demonstrated that the cross-linking bond between ribosomal proteins S5 and S8 involves primarily the residues Lys-93 of protein S8 and the COOH-terminal lysine (Lys-166) of ribosomal protein S5. This result is substantiated by the finding that a mutant carrying an altered S5 lacking the COOH-terminal lysine yields a greatly reduced amount of S5-S8 cross-link. In addition to the points of cross-linking it was found that Lys-30, Lys-68, and Lys-86 of S8 and Lys-5 of S5 react with dimethylsuberimidate, indicating that these residues are available for reaction and suggesting their topographical localization on the ribosomal surface.

Amino Acid Sequence↗