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A Cataldi

Publications and source records attributed to A Cataldi.

At least 163 records · Page 9Linked to original sources
PubMed1981

[Characterization of the convoluted seminiferous tubule wall. I. Ultrastructural aspects after the ligation of the vas deferens and the efferent tubules].

The structure of the wall of the rat seminiferous tubules has been studied by electron microscopy. No significant modifications have been revealed after the ligature of the vas deferens while on the contrary the ligature of the efferent ductules produces a reduction of the contractile filaments and of the pinocytosis vesicles, as well as an increase of the amount of collagen fibers in the basal membrane.

Animals↗
PubMedDate not supplied

A western blot characterization of Mycobacterium bovis antigens recognized by cattle sera.

The immune response to Mycobacterium bovis in cattle was assessed by Western blot. The antibody recognition pattern to M. bovis whole cell extracts and culture supernatant antigens was studied by using sera from M. bovis-infected (n = 62) and healthy (n = 38) cattle. Although the recognition patterns were highly variable, some proteins were regularly detected, mainly those with molecular masses of 17, 23, 28, 42, 66, 71 and 80 kDa in cellular extracts, and with molecular masses of 23 and 33 kDa in supernatants. Whole cell extract antigens were more frequently recognized than culture supernatant antigens. Healthy controls produced only a weak antibody response. The antibody response was variable, depending on tuberculosis stage. In early stages very few antibodies were detected. A response against the 66-kDa stress protein was mounted in intermediate tuberculosis and remained stable in more advanced disease. In late diseases, the preferentially recognized antigens were a 28-kDa cellular protein and supernatant antigens. The 28-kDa protein was studied in some detail. As determined by using monoclonal antibodies, the 28-kDa protein is different from superoxide dismutase. This protein aggregated in stored cell extracts and was not totally transferred to nitrocellulose. The principal conclusions of this work are: (i) whole cell extract proteins are more frequently recognized than the secreted proteins and (ii) a 28-kDa protein is a major antigen in late disease.

Animals↗
PubMedDate not supplied

Correlations between protein kinase C zeta signaling and morphological modifications during rat heart development and aging.

From birth to aging the heart undergoes functional changes reflecting biochemical and ultrastructural modifications which imply apoptosis. This is a physiological process resulting from genetic programs closely associated with development and aging. During development apoptosis eliminates redundant cells leading to heart remodeling, while during aging it eliminates damaged or exhausted cells. In the present paper we analyze some molecular mechanisms involved with heart morphological modifications, especially in the neonatal heart which displays different features in the subendocardial and myocardial area. The high number of subendocardial apoptotic cells and the inverted ratio of Bcl-2/Bax molecule expression in the two heart compartments led us to hypothesize a different metabolism in the myocardium as compared with subendocardium. Moreover, we propose that PKC zeta may mediate this different response by activating Nf-kB pathway and by maintaining the balance between hypertrophic growth and apoptosis involved with remodeling of neonatal heart. Further, we underline that in the aged heart, where this pathway is not activated, such balance is not maintained.

Aging↗
PubMedDate not supplied

Evaluation of beta-endorphin secretion in patients suffering from episodic cluster headache.

In order to obtain data regarding peripheral levels of beta-endorphin in head pain syndromes, we evaluated the plasma beta-endorphin secretory pattern in 12 adult male patients suffering from cluster headache. Blood samples were drawn every 2 hours for a 24-hour period, and in addition at 30-minute intervals for 120 minutes during cluster attacks. The same sampling was repeated during an asymptomatic period. Cluster headache patients showed no significant beta-endorphin circadian rhythm and a delayed acrophase during cluster periods compared with that recorded in the remission period and in normal subjects. Eighteen cluster headache attacks were recorded during the study day, 13 (72%) of which were followed by a significant increase in beta-endorphin levels. No correlation was found between beta-endorphin maximum net increase and intensity and/or duration of pain. These data suggest the hypothesis of a temporary alteration of beta-endorphin circadian secretion, probably related to involvement of neural structures controlling biorhythm pacemakers.

Adult↗
PubMedDate not supplied

Caspase-3 is dually regulated by apoptogenic factors mitochondrial release and by SAPK/JNK metabolic pathway in leukemic cells exposed to etoposide-ionizing radiation combined treatment.

Ionizing radiation induces a series of multiple intracellular events which can lead to activation of caspases, cytoplasmic proteases involved in the occurrence of apoptosis. The response of leukemic cells to ionizing radiation is amplified when they have been pre-treated with the anticancer drug etoposide, therefore the aim of this work has been to establish the lowest etoposide concentration combined with the lowest ionizing radiation dose to obtain the best antineoplastic response. Two leukemic cell lines, HL-60 and Jurkat, employed in this study demonstrated different sensitivities to ionizing radiation and to etoposide treatment, with Jurkat T cells requiring a higher dose (1 microM) to display cell cycle perturbation and apoptotic DNA damage similar to those seen in HL-60. We hypothesize that this kind of response could be mediated by mitochondrial release of apoptogenic factors and by SAPK/JNK metabolic pathway activation, both leading to caspase-3 cleavage. All in all these results provide insight into the sensitivity or resistance of leukemic cells to antineoplastic agents and identify molecular targets for rational therapeutic intervention strategies.

Antineoplastic Agents, Phytogenic↗
PubMedDate not supplied

Protein kinase C zeta regulation of hypertrophic and apoptotic events occurring during rat neonatal heart development and growth.

The development and growth of the rat heart implies hyperplasia, which stops at birth, and hypertrophy, allowing cardiac mass to grow in response to programmed genetic events along with to haemodynamic overload. Moreover, hypertrophy is accomplished to apoptosis which controls the final number of myocardial cells, deletes vestigial structures, and takes part in remodelling the organ. Since at the basis of all these processes, which lead to the complete development of the heart, the activation of specific signalling pathways underlies, attention has been addressed to the role played in vivo by Protein Kinase C zeta (PKC zeta) in regulating NF-kB signalling system and intrinsic mitochondrial apoptotic route at days 1, 4, 10 and 22 of rat life. In fact, a role has been assigned to PKC zeta in indirectly phosphorylating IKBa, which peaks between 10 and 22 days, through a IKK determining, in turn, NF-kB activation, concomitantly to cytochrome c/Apaf 1 co-localization in the cytoplasm and caspase-9/caspase-3 activation, which leads to the occurrence of apoptosis. Thus a key role for PKC zeta in regulating the hypertrophic and apoptotic events leading to establishment of complete function in rat neonatal heart is here suggested.

Animals↗
PubMedDate not supplied

Nuclear protein kinase C-delta: a possible check-point of cell cycle progression.

Protein kinase Cs (PKCs) belong to a serine/threonine kinase family, ubiquitously expressed and claimed to be involved in physiological processes including apoptosis, cell growth and differentiation. The question of the subcellular localization and activity of PKCs remains to be clarified. Here we report that nuclear PKC-delta cooperates to regulate the S-G2/M phase transition of cell cycle, apparently being associated to chromosome condensation and alignment on the metaphase plate.

Cell Cycle↗
PubMedDate not supplied

Leptin levels in nonalcoholic steatohepatitis and chronic hepatitis C.

BACKGROUND/AIMS: Leptin is a peptide which regulates food intake and energy expenditure. Moreover, it is involved in the homeostasis of body composition and is linked to the regulation of insulin signaling, thus playing an important role in liver fat storage. Steatosis is a common finding in chronic hepatitis C, and both viral and metabolic factors have been suggested to explain the presence of this histological characteristic. In order to study leptin in chronic liver disease characterized by the presence of steatosis, we evaluated its serum levels in patients with nonalcoholic steatohepatitis (NASH), in chronic hepatitis C (CHC) patients with no histological findings of steatosis, and CHC patients with steatosis but no risk factors for its development. METHODOLOGY: We studied 6 male patients with NASH whose diagnosis was made on the basis of histological findings and clinical criteria. From among a cohort of 170 CHC patients we put together 2 groups of 6 male patients each (with or without steatosis at liver biopsy examination), who had no risk factors for NASH. Male patients were chosen in order to avoid gender influence on leptin levels. Further criteria for admission were similar impairment of liver metabolic function as assessed by the monoethylglycinexylidide (MEGX) test and, in patients with CHC, similar body mass index (BMI) and histological staging. Moreover, we evaluated leptin/BMI ratio, in order to rule out BMI influence on leptin levels. Leptin levels were assessed by means of radioimmunoassay. RESULTS: We found that BMI was higher in NASH compared to CHC (27.2 +/- 2.9 vs. 23.9 +/- 1.8; p = 0.01). Analysis of serum leptin levels showed an increasing trend starting from patients with CHC without steatosis (3.2 +/- 0.4 ng/ml), through CHC patients with steatosis (4.2 +/- 0.7 ng/ml) up to patients with NASH (5.7 +/- 2 ng/ml), although the differences observed were not statistically significant. Moreover, the ratio of leptin to BMI also followed the same trend showing increasing values (CHC without steatosis = 0.04 +/- 0.02; CHC patients with steatosis = 0.17 +/- 0.03; NASH = 0.203 +/- 0.07). Leptin levels and BMI showed a significant relationship (n = 18; r = 0.60; p < 0.01). CONCLUSIONS: The increasing trend observed in leptin serum levels among the different groups of patients showed that in chronic liver disease characterized by the presence of steatosis, leptin signaling is preserved. Moreover, CHC factors different from the metabolic ones should be investigated in order to explain the presence of steatosis. Further studies on broader groups of patients are needed to verify these preliminary results.

Adult↗
PubMedDate not supplied

Evaluation of a QIAamp DNA stool purification kit for Shiga-toxigenic Escherichia coli detection in bovine fecal swabs by PCR.

A commercial kit intended for Taq polymerase inhibitor removal was tested to detect Shiga-toxigenic Escherichia coli (STEC) by polymersase chain reaction (PCR) directly from cattle fecal samples. Forty-five samples were analysed for the presence of stx genes. Results were compared to those obtained by two other methods: amplification of DNA purified by a non-commercial procedure (heat lysis protocol), and amplification of DNA from samples cultured in solid media, commonly used in our lab. Identical numbers of positive samples (33/45, 73 %) were obtained with the QIAamp DNA stool purification kit and the culturing procedure, suggesting an adequate removal of inhibitors that interfere in PCR amplification from the feces. Besides, the number of positive samples detected using DNA purified by the non-commercial protocol was lower, 25/39 (64%) than that achieved by using the kit. In conclusion, the use of the QIAamp DNA stool purification kit provided a rapid stx gene detection by PCR in bovine fecal samples.

Animals↗
PubMedDate not supplied

First description of Mycobacterium tuberculosis Beijing genotype in Argentina.

During a population-based study to genotype isolates of Mycobacterium tuberculosis from Buenos Aires Northern suburbs, we found isolates with molecular patterns related to those of the Beijing genotype. Five out of 590 (0.85%) patients had isolates with spoligopattern identical to that of the Beijing family. Since two of these isolates showed identical IS6110RFLP pattern, we found only four different patterns containing 11 to 19 bands. The isolates were obtained from young people (including a 7 years-old child) who were born in Argentina, and were living in a small area of our region. However, conventional contact tracing did not prove epidemiological linkage among them. These isolates were fully drug-susceptible to the first-line drugs. The comparison of the IS6110RFLP patterns from our isolates against a set of 19 reference Beijing patterns from the RIVM (The Netherlands) confirmed that the strains belonged to the Beijing lineage. These findings might be partially explained by the important migration phenomena occurred during the last decade. Further surveillance studies would help in the following of Beijing family strain dissemination in our community.

Adolescent↗
PubMedDate not supplied

Long term therapy with recombinant interferon alpha 2 b in patients with chronic hepatitis C: effects on thyroid function and autoantibodies.

Twelve anti HCV-positive patients (8 males and 4 females; 37-62 yrs) suffering from chronic active viral hepatitis have been evaluated in order to determine serum thyroid hormones and autoantibody pattern during recombinant interferon alpha 2b (IFN-alpha 2b) therapy. The interferon was given subcutaneously three times per week for six months in a single standard dose of 3 MU. For a further six months 5 patients (Group A) received the same interferon at 1MU dose three times per week and 7 (Group B) had no treatment. Serum T3, T4, FT4, TBG, TSH, TGAb and TMAb were determined on serum collected before the start of the treatment and every month for 12 months thereafter. Except for one case, in which a transient reduction in thyroid hormone values and an increase in TSH levels was recorded, none of the patients studied showed a significant variation of serum hormonal parameters or appearance of pathological TGAb and/or TMAb levels. The data indicate that the administration of recombinant IFN-alpha 2b to HCV positive chronic active hepatitis patients at the dose and schedule employed in the present study may result in a reduction in the incidence of thyroid dysfunction related to the IFN therapy.

Adult↗
PubMedDate not supplied

[Chronic pain in the hindfoot: computed tomography as a complement in clinico-radiographic evaluation. A study of 38 cases].

A series of 38 patients affected with a chronically painful hindfoot underwent CT as a complement to conventional radiography and/or clinics for suspected bone and joint disorders. In all, CT depicted 20 bone abnormalities, i.e., 7 talar osteochondrites, 1 talar osteoid osteoma, 3 subtalar coalitions, 1 calcaneal bone lipoma, 5 posttraumatic talar deformities and 3 posttraumatic calcaneal deformities. Conventional radiography missed 6 of these abnormalities, i.e., 3 talar osteochondrites and 3 subtalar coalitions. In 5 cases CT gave additional information, useful both for the diagnosis (demonstration of fat in the bone lipoma) and to clarify the painful symptoms (2 patients with subtalar osteoarthrosis and 2 with peroneal tendon impingement). Twelve of 15 clinically suspected soft tissue abnormalities were also demonstrated, namely, 2 tibiotalar ligament injuries, 1 sprain of the interosseous ligament of tarsal sinus, 2 cases of accessory soleus muscle, 4 peroneal tendon injuries, 2 posterior tibial tendon injuries and 1 long flexor tendon injury. In the extant 3 patients with suspected bone disorders, both radiography and CT found nothing to confirm the clinical suspicion. To conclude, the authors believe CT to play a major diagnostic role, thanks to its capabilities in demonstrating the abnormal changes underlying chronically painful hindfoot conditions.

Calcaneus↗