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Biomedical subjects

A Basile

Publications and source records attributed to A Basile.

At least 19 recordsLinked to original sources

Aminoglycoside neurotoxicity involves NMDA receptor activation.

Previous studies have led to the hypothesis that the ototoxicity produced by aminoglycoside antibiotics involves the excitotoxic activation of cochlear NMDA receptors. If this hypothesis is correct, then these antibiotics should also injure neurons within the brain. Because aminoglycosides do not readily penetrate the blood brain barrier, we examined the effects of the aminoglycoside neomycin following intrastriatal injection. Neomycin (10-250 nmol) produced dose-dependent striatal damage manifested as an increased gliosis as measured by: (1) [3H]PK-11195 binding, (2) staining for the astrocytic marker glial fibrillary acidic protein (GFAP) and (3) staining for OX-6, an MHC class II antigen expressed by microglia and macrophages. Co-injection of subthreshhold doses of NMDA potentiates the striatal damage produced by neomycin (10 nmol). Moreover, neomycin-induced striatal damage is attenuated by a combination of the NMDA antagonists ifenprodil and 5, 7-dichlorokynurenic acid. Intrastriatal administration of compounds structurally related to neomycin, but devoid of modulatory actions at NMDA receptors (paromamine and 2-deoxystreptamine), fail to produce neuronal damage. These data support the hypothesis that aminoglycoside-induced ototoxicity is, in part, an excitotoxic process involving the activation of NMDA receptors. Moreover, aminoglycosides may damage the central nervous system in individuals with compromised blood brain barriers.

Aminoglycosides

Structural analysis and quantitative evaluation of the modifications produced in human hemoglobin by methyl bromide using mass spectrometry and Edman degradation.

The present study reports a procedure developed for the identification and quantitative analysis of the adducts formed by interaction of methyl bromide with human hemoglobin, based on combined analysis by electrospray mass spectrometry and automated Edman degradation of either intact globin chains or tryptic peptides of globin chains. The procedure has allowed identification of the reactive sites in human hemoglobin, and has been applied to the analysis of samples modified in vitro by methyl bromide. The results obtained represent the basis for the complete structural characterization of the modified hemoglobin and demonstrate the usefulness of the proposed analytical approach for the evaluation of the degree of alkylation and the identification of modified amino acids in proteins.

Amino Acid Sequence

Interferon-gamma inhibits expression of the long pentraxin PTX3 in human monocytes.

PTX3 is a prototypic long pentraxin expressed by various cell types, most prominently monocytes and endothelial cells, in response to interleukin-1 (IL-1), tumor necrosis factor (TNF) and bacterial products. In the present report, we show that interferon-gamma (IFN-gamma) inhibits the expression of the PTX3 gene induced by exposure to IL-1, TNF or lipopolysaccharide in human monocytes. This effect is dose dependent and observable when IFN-gamma is added from 24 h before up to 3 h after the addition of IL-1. While the time course of the IL-1-induced PTX3 mRNA expression is not affected, IFN-gamma reduces the stability of the PTX3 mRNA as well as its transcription. The inhibition of PTX3 expression is restricted to monocytes in that no inhibition occurs in cytokine-stimulated fibroblasts and endothelial cells. Under the same conditions, as expected, IFN-gamma augmented monocyte chemotactic protein-1 expression in the same cell preparations. PTX3 protein secretion by activated monocytes is also suppressed by exposure to IFN-gamma. Altogether, these data identify a negative pathway of regulation mediated by IFN-gamma, which may occur under inflammatory conditions.

C-Reactive Protein

Antibacterial activity in Pleurochaete squarrosa extract (Bryophyta).

An acetone extract of the moss Pleurochaete squarrosa was tested against eleven bacterial strains, some of which are pathogenous for man. The extract was active on some Gram-negative strains. Antibacterial activity of the extract, expressed as MICs, was compared with three reference antibiotics. Acute toxicity assay was performed in Balb C mice.

Acetone

Twenty-four-hour intravenous and oral tracer studies with L-[1-13C]-2-aminoadipic acid and L-[1-13C]lysine as tracers at generous nitrogen and lysine intakes in healthy adults.

BACKGROUND: This is a continuation of investigations of the relations between amino acid kinetics and amino acid dietary requirements in healthy adults. OBJECTIVE: The aim was to investigate the 24-h pattern and rate of the metabolism of an L-[1-13C]-2-aminoadipic acid ([13C]AAA) tracer and of whole-body L-[1-13C]lysine ([13C]lysine) oxidation and balance in healthy, young adults receiving a generous intake of lysine. DESIGN: Thirteen healthy adults were given an adequate, L-amino acid-based diet supplying 77 mg lysine x kg(-1) x d(-1) for 6 d before the tracer studies. Two subjects received [13C]AAA intravenously and 2 received it orally; 3 subjects received [13C]lysine intravenously and 6 received it orally. We measured 13CO2 output, plasma [13C]AAA and [13C]lysine enrichment, and urinary [13C]AAA. RESULTS: [13C]AAA oxidation was estimated to be higher after the orally administered than after the intravenously administer tracer; plasma [13C]AAA was similar to urinary [13C]AAA. Whole-body lysine oxidation showed a rhythm that was induced by meal feeding. The intravenous [13C]lysine tracer gave mean estimates of lysine balances (lysine intake minus oxidation) that apparently were too low (-15.7 mg x kg(-1) x d(-1)) or too high (16.6 mg x kg(-1) x d(-1), P < 0.05 from zero balance) on the basis of urinary [13C]AAA or plasma [13C]lysine estimates of oxidation, respectively. For the orally administered tracer and plasma [13C]lysine enrichment, the mean balance was slightly positive (8.7 mg x kg(-1) x d(-1), P < 0.05 from zero). CONCLUSIONS: Use of urinary [13C]AAA as an index of the enrichment of the precursor pool did not appear to significantly improve the estimate of the fasting and feeding components of daily lysine balance. For estimates of daily, whole-body lysine oxidation, we propose use of plasma [13C]lysine with a 24-h, orally administered tracer protocol.

2-Aminoadipic Acid

Antioxidant properties of Lunularia cruciata (Bryophyta) extract.

The effects of Lunularia cruciata (L.) Dum (Bryophyta) acetonic extract was studied in vitro by means of luminol-dependent chemiluminescence (CL) emission from human peripheral whole blood phagocytes and isolated polymorphonuclear leukocytes (PMNs). L. cruciata adult thalli underwent extraction with acetone. CL emission was evaluated in an automated luminometer, measuring the oxygen free-radical production by phagocytes incubated with opsonized zymosan (OZ) or phorbol myristate acetate (PMA), in absence or in presence of various concentrations of L. cruciata extract. The CL results indicated that L. cruciata induced significant changes in light emission from whole blood phagocytes, as well as isolated PMNs. Its inhibitory activity was more evident when resting isolated PMNs were studied. When the cells were activated, the greatest inhibitory effect was observed with PMA. The L. cruciata activity could be caused by several compounds, such as flavonoids and/or sesquiterpenes, present in the acetonic extract.

Antioxidants

Characterization of the promoter for the human long pentraxin PTX3. Role of NF-kappaB in tumor necrosis factor-alpha and interleukin-1beta regulation.

The "long pentraxins" are an emerging family of genes that have conserved in their carboxy-terminal halves a pentraxin domain homologous to the prototypical acute phase protein pentraxins (C-reactive protein and serum amyloid P component) and acquired novel amino-terminal domains. In this report, a genomic fragment of 1371 nucleotides from the human "long pentraxin" gene PTX3 is characterized as a promoter on tumor necrosis factor-alpha (TNFalpha) and interleukin (IL)-1beta exposure in transfected 8387 human fibroblasts by chloramphenicol acetyltransferase and RNase protection assays. In the same cells, the PTX3 promoter does not respond to IL-6 stimulation. Furthermore, IL-1beta and TNFalpha responsiveness is not seen in the Hep 3B hepatoma cell line. The minimal promoter contains one NF-kappaB element which is shown to be necessary for induction and able to bind p50 homodimers and p65 heterodimers but not c-Rel. Mutants in this site lose the ability to bind NF-kappaB proteins and to respond to TNFalpha and IL-1beta in functional assays. Sp1- and AP-1 binding sites lying in proximity to the NF-kappaB site do not seem to play a major role for cytokine responsiveness. Finally, cotransfection experiments with expression vectors validate that the natural promoter contains a functional NF-kappaB site.

Animals

IL-2-regulated expression of the monocyte chemotactic protein-1 receptor (CCR2) in human NK cells: characterization of a predominant 3.4-kilobase transcript containing CCR2B and CCR2A sequences.

NK cells migrate in response to C-C chemokines, including monocyte chemotactic protein-1 (MCP-1) and MCP-3. Increased migration was observed in IL-2-activated NK cells. It was therefore of interest to define the expression in resting and activated NK cells of the MCP-1 receptor (CCR2) for which two cDNAs (A and B) have been described. Specific oligonucleotides and reverse-transcriptase PCR revealed the presence in activated NK cells and mononuclear phagocytes of the fragments expected on the basis of the reported cDNAs. In addition, amplification with a common A/B- and an A-specific oligonucleotide yielded an unexpected, abundant, 1649-bp fragment. Sequence analysis as well as Northern blotting and RNase protection with different probes revealed that the CCR2 gene is expressed in activated NK cells and mononuclear phagocytes as a predominant long transcript (3.4 kb) consisting of CCR2B, followed by a novel sequence (X), corresponding to an intron in the genome, and by a CCR2A-specific portion. The predominant long transcript is polyadenylated and present in the cytoplasm. The augmented migratory capacity of IL-2 activated vs resting NK cells was associated with increased CCR2 transcript levels.

Base Sequence

[Klippel-Trenaunay syndrome].

The Klippel-Trenaunay syndrome is a rare congenital pathology which includes varices, hemangiomas and hypertrophy of limbs. The Authors report two cases and pay particular attention to the diagnostic and therapeutical protocols. Although these aspects are still open questions, the Authors conclude that conservative therapy is often sufficient while surgery is requested only in the severe forms.

Adult

Distinct mechanisms for Ca2+ entry induced by OKT3 and Ca2+ depletion in Jurkat T cells.

Ca2+ influx triggered by antigen binding to T cell receptors (TCR) is an early event in T cell activation. An additional Ca2+ influx induced by depletion of intracellular Ca2+ (CDCI) has been characterized in human Jurkat T cells that is both temporally and mechanistically distinct from TCR-mediated Ca2+ influx (TCRCI). Both TCRCI and CDCI were insensitive to voltage-gated Ca2+ channel antagonists (e.g., nifedipine, verapamil, and omega-conotoxin G) and pertussis toxin, yet were voltage-sensitive and inhibited by SKF 96365 (a receptor-gated Ca2+ channel blocker) and cholera toxin. However, TCRCI but not CDCI was associated with a significant increase in inositol phosphate (IP chi) levels and inhibited by phorbol ester, while CDCI but not TCRCI was inhibited by Sr2+, forskolin (FSK), and 1,9-dideoxy FSK in a cAMP-independent fashion. Moreover, TCR stimulation did not deplete thapsigargin-sensitive Ca2+ stores, suggesting that TCRCI is not merely a consequence of Ca2+ depletion. These results indicate that Ca2+ entry following the depletion of intracellular Ca2+ stores or TCR stimulation occur through distinct cellular mechanisms coexisting in Jurkat T cells.

8-Bromo Cyclic Adenosine Monophosphate

Characterization of a new gene that encodes a functional MHV receptor and progress in the identification of the virus-binding site(s).

Several splice variants of the murine biliary glycoprotein 1 (Bgp 1) gene in the carcinoembryonic antigen gene superfamily serve as cellular receptors for mouse hepatitis virus. RNAPCR and immunoblot analysis of the receptor in inbred mouse strains showed that the glycoproteins expressed in SJL/J mice are encoded by an allelic variant of the Bgp 1 gene, named Bgp 1b. We recently cloned and characterized a second gene, Bgp 2, that encodes a functional MHV receptor glycoprotein which is not recognized by anti-MHVR MAb-CC1. A third gene related to Bgp 1 was cloned and expressed and shown to encode a soluble protein called Cea-10 that differs significantly in its N-terminal domain from Bgp 1 and Bgp 2. Chimeric proteins constructed between the different murine Bgps and point mutations in the prototype MHV receptor, Bgp 1a or MHVR, were analyzed to further characterize the MAb-CC1-binding and virus-binding domains within the N terminal domain of the receptor. Thus, the murine host for MHV expresses multiple splice variants of mRNAs encoded by several different Bgp-related genes which differ in their ability to serve as MHV receptors. The differential expression of these genes in different murine tissues may help to explain the tissue tropism of MHV strains.

Alternative Splicing

Renal tubular dysfunction in chronic alcohol abuse--effects of abstinence.

BACKGROUND: Alcohol abuse may be accompanied by a variety of disorders of electrolyte and acid-base metabolism. The role of the kidney in the pathogenesis of these disturbances is obscure. We sought to evaluate the alcohol-induced abnormalities of renal function and improvement during abstinence and to assess the relation between renal dysfunction and electrolyte and acid-base disorders. METHODS: We measured biochemical constituents of blood and renal function before and after four weeks of abstinence in 61 patients with chronic alcoholism who had little or no liver disease. RESULTS: On admission, 18 patients (30 percent) had hypophosphatemia and hypomagnesemia, 13 patients (21 percent) had hypocalcemia, and 8 patients (13 percent) had hypokalemia. Twenty-two patients (36 percent) had a variety of simple and mixed acid-base disorders. Twenty of these patients had metabolic acidosis, and among them, 80 percent had alcoholic acidosis. A wide range of defects in renal tubular function, with normal glomerular filtration rate, were detected in these patients. The defects included decreases in the threshold and maximal reabsorptive ability for glucose (38 percent of patients) and in the renal threshold for phosphate excretion (36 percent); increases in the fractional excretion of beta 2-microglobulin (38 percent), uric acid (12 percent), calcium (23 percent), and magnesium (21 percent); and aminoaciduria (38 percent). Seventeen patients (28 percent) had a defect in tubular acidification, and five an impairment in urinary concentrating ability. Urinary excretion of N-acetyl-beta-D-glucosaminidase and alanine aminopeptidase were increased in 41 and 34 percent of patients, respectively. The abnormalities of blood chemistry and renal tubular function disappeared after four weeks of abstinence. CONCLUSIONS: Transient defects in renal tubular function are common in patients with chronic alcoholism and may contribute to their abnormalities of serum electrolyte and blood acid-base profiles.

Acid-Base Imbalance

[Male genito-urinary tract infection caused by Chlamydia trachomatis and seminal characteristics: use of minocycline].

The authors evaluated the activity of Minocycline in 30 male patients with urinary tract infection caused by Chlamydia trachomatis (Ct) and alterations of the seminal parameters using three different dosage schedules (100 mg/day for 10 days, 200 mg/day for 10 days and 200 mg/day for 20 days). At baseline, at the end of therapy and one month after clinical and bacteriological parameters and seminal characteristics, including some sperm function tests (acridine orange test to study chromatin heterogeneity; triple staining technique, to study acrosome; swim-up technique, to study the sperm kinetics) were verified. The seminal characteristics were checked again three and six months after the end of the therapy. All the results show that Minocycline is an excellent drug for the treatment of urinary tract infection caused by Chlamydia trachomatis both for its therapeutic efficacy and for the absence of side effects. Although 10 days cycles using 1 cap/day are sufficient to eliminate inflammation and infection, in order to obtain more valid results it is preferable to use the following dosage schedule: 200 mg/day of antibiotic (100 mg twice daily) for 10 days. The results of our trial show that in cases of Chlamydia trachomatis infection associated with dispermia (reduced nemaspermic concentration, hypomotility, teratozoospermia, increased number of leucocytes), if the parameters of sperm function are within normal limits, the resolution of the infection is usually followed by a recovery of normozoospermia. Follow-up performed 3 and 6 months after the end of treatment showed an increase in the number of spermatozoa, a percentage increase in their motility, mostly in the progressive motility, and a reduction of the atypical forms.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Malignant change in a benign pulmonary hamartoma.

Sarcomatous transformation in a longstanding, clinically silent hamartoma is reported. Malignant change occurred shortly after resection, suggesting that surgical manipulation may have played a part.

Female

Carcinoma of the male breast and ocular metastases.

Breast carcinoma in males associated with ocular metastases is not often observed. A case is reported with review of the literature. Medical management is satisfactory in case of metastases and enucleation is suggested for severe pain.

Adenocarcinoma, Scirrhous

Cephalometric airway analysis in obstructive sleep apnea syndrome.

In obstructive sleep apnea syndrome, polysomnograms characterize the nature and severity of the disorder but, rarely, its specific site. Therefore, 90 patients with documented obstructive sleep apnea were evaluated by cephalometric technique, with special attention paid to the size and position of the soft palate and uvula, volume and position of the tongue, mandibulo-maxillary relationship, hyoid position, and size of the pharyngeal airway space. Results showed major differences between control patients and patients with obstructive sleep apnea in over 50% (30/52) of the objectively measured indices of the cephalometric airway. Further, many changes in the cephalograms of these patients can be correlated with disease severity.

Adult