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Biomedical subjects

F Marchesi

Publications and source records attributed to F Marchesi.

At least 19 recordsLinked to original sources
PubMed2006

Immunohistochemical detection of Ym1/Ym2 chitinase-like lectins associated with hyalinosis and polypoid adenomas of the transitional epithelium in a mouse with acute myeloid leukemia.

An 8-month-old PML/RARalpha knock-in female mouse developed a promyelocytic-like myeloid leukemia with an expected latency. At necropsy, besides the typical findings associated with myeloid leukemia, a severe unilateral hydronephrosis was observed. By histopathologic examination, 2 polypoid adenomas arising from the transitional epithelium of the renal pelvis and ureter were detected. The epithelial cells of the polypoid adenomas showed accumulation of hyaline eosinophilic material within the cytoplasm. Large amounts of extracellular eosinophilic crystals were also associated with the transitional cell adenomas. Immunohistochemical analysis revealed that the eosinophilic intracytoplasmic material and the extracellular eosinophilic crystals were composed of Ym proteins. A unilateral hyaline droplet tubular nephropathy was associated with the myeloid leukemia. Expression of Ym proteins characterized both the neoplastic myeloid infiltrates and the tubular hyaline droplets. In the present PML/RARalpha knock-in female mouse, the accumulation of Ym proteins associated with the myeloid leukemia and with the polypoid adenomas of the transitional epithelium underlies 2 distinct pathogenetic mechanisms.

Adenoma↗
PubMed2003

Eosinophilic crystals as a distinctive morphologic feature of a hyaline droplet nephropathy in a mouse model of acute myelogenous leukaemia.

Eosinophilic crystals have been described in the upper and lower respiratory tract, gall bladder, intrahepatic bile ducts and glandular stomach of different laboratory mice strains. They have been recently identified as chitinase-like (Ym1/Ym2) proteins. Here we describe the occurrence of eosinophilic crystals in the renal tubules of mice with experimentally induced acute myelogenous leukaemia. Fourteen FVB/N and 29 129Sv mice of both sexes, 8-10 weeks of age, were employed to establish a model of human acute myelogenous leukaemia. Nine mice that developed a widespread acute myelogenous leukaemia revealed the presence of eosinophilic crystals in renal tubules. The presence of eosinophilic crystals in the kidneys was constantly associated with a hyaline droplet nephropathy. Immunohistochemistry showed that the crystals and the hyaline droplets were composed of chitinase-like (Ym1/Ym2) proteins. Furthermore, immunoreactivity for Ym1/Ym2 proteins was also detected in the crystalline material stored in the cytoplasm of large macrophage-like cells or in extracellular localization within the leukaemic infiltrates. On the basis of our results we hypothesize that the detection of the Ym1/Ym2 proteins in the urine of mice might represent a feasible indicator of the burden and progression of the leukaemic condition in our murine model.

Animals↗
PubMed2001

Hernioplasty and simultaneous laparoscopic cholecystectomy: a prospective randomized study of open tension-free versus laparoscopic inguinal hernia repair.

BACKGROUND: The laparoscopic repair of unilateral primary groin hernia remains controversial. This randomized study evaluates the outcome of the laparoscopic technique in hernia repair in patients undergoing simultaneous laparoscopic cholecystectomy (LC) and compares laparoscopic repair with tension-free open groin hernia repair. METHODS: Sixty-four low-risk patients with symptomatic chronic calculous cholecystitis and synchronous unilateral primary inguinal hernia were randomized to undergo either laparoscopic transabdominal preperitoneal mesh hernia repair (TAPP) and LC or LC and open tension-free hernia repair. RESULTS: The operating time was longer in the TAPP and LC group (mean +/- SD = 121 +/- 32 minutes) than in the LC and open group (95 +/- 27 minutes) (P <.01). The mean operating costs were higher in the TAPP and LC group ($1235 versus $1080) (P <.03). The intensity of postoperative pain at rest was greater in the LC and open group at 24 hours (P <.01) and 48 hours (P <.05), with a greater consumption of pain medication (P <.01). No differences between the 2 groups were found in terms of postoperative complications, disability period before return to work, or hernia recurrences. CONCLUSIONS: The totally laparoscopic procedure does not result in a significant benefit other than improved comfort in the first 2 postoperative days. However, laparoscopic hernia repair is considerably more difficult to perform than open tension-free hernioplasty. Thus, the totally laparoscopic approach should be performed only by experienced laparoscopic surgeons with special expertise in hernia surgery.

Adult↗
PubMed2001

Long-term oral L-arginine administration improves peripheral and hepatic insulin sensitivity in type 2 diabetic patients.

UNLABELLED: The aim of this study was to evaluate whether long-term administration of arginine acting through a normalization of NO/cyclic-guanosine-3' 5'-cyclic monophosphate (cGMP) pathway was able to ameliorate peripheral and hepatic insulin sensitivity in 12 lean type 2 diabetic patients. RESEARCH DESIGN AND METHODS: A double-blind study was performed for 3 months. In the first month, patients were treated with their usual diet. Then they were randomly allocated into to groups. In group 1, patients were treated with diet plus placebo (orally three times per day) for 2 months. In group 2 patients were treated for 1 month with diet plus placebo orally, three times per day) and then for 1 month with diet plus L-arginine (3 g three times per day). At the end of the first and the second month of therapy, patients underwent a euglycemic-hyperinsulinemic clamp combined with [6,6-2H2] glucose infusion. A total of 10 normal subjects underwent the same test as control subjects. RESULTS: In group 1, no changes in basal cGMP levels, systolic blood pressure, forearm blood flow, glucose disposal, and endogenous glucose production were observed throughout. In group 2, L-arginine normalized basal cGMP levels and significantly increased forearm blood flow by 36% and glucose disposal during the clamp by 34% whereas it decreased systolic blood pressure and endogenous glucose production by 14 and 29%, respectively. However, compared with normal subjects, L-arginine treatment was not able to completely overcome the defect in glucose disposal. CONCLUSIONS: L-Arginine treatment significantly improves but does not completely normalizc peripheral and hepatic insulin sensitivity in type 2 diabetic patients.

Administration, Oral↗
PubMed2000

Inflammatory cytokines and related genes are induced in the rat hippocampus by limbic status epilepticus.

Limbic status epilepticus was induced in rats by unilateral 60-min electrical stimulation of the CA3 region of the ventral hippocampus. As assessed by RT-PCR followed by Southern blot analysis, transcripts of interleukin-1beta, interleukin-6, interleukin-1 receptor antagonist and inducible nitric oxide synthase were significantly increased 2 h after status epilepticus in the stimulated hippocampus. Induction was maximal at 6 h for interleukin-1beta (445%), interleukin-6 (405%) and tumour necrosis factor-alpha (264%) and at 24 h for interleukin-1 receptor antagonist (494%) and inducible nitric oxide synthase (432%). In rats with spontaneous seizures (60 days after status epilepticus), interleukin-1beta mRNA was still higher than controls (241%). Immunocytochemical staining of interleukin-1beta, interleukin-6 and tumour necrosis factor-alpha was enhanced in glia with a time-course similar to that of the respective transcripts. Sixty days after status epilepticus, interleukin-1beta immunoreactivity was increased exclusively in neurons in one third of the animals. Multiple intracerebroventricular injections of interleukin-1 receptor antagonist (0.5 microg/3 microL) significantly decreased the severity of behavioural convulsions during electrical stimulation and selectively reduced tumour necrosis factor-alpha content in the hippocampus measured 18 h after status epilepticus. Thus, the induction of spontaneously recurring seizures in rats involves the activation of inflammatory cytokines and related pro- and anti-inflammatory genes in the hippocampus. These changes may play an active role in hyperexcitability of the epileptic tissue.

Animals↗
PubMed1999

Interleukin-1beta immunoreactivity and microglia are enhanced in the rat hippocampus by focal kainate application: functional evidence for enhancement of electrographic seizures.

Using immunocytochemistry and ELISA, we investigated the production of interleukin (IL)-1beta in the rat hippocampus after focal application of kainic acid inducing electroencephalographic (EEG) seizures and CA3 neuronal cell loss. Next, we studied whether EEG seizures per se induced IL-1beta and microglia changes in the hippocampus using bicuculline as a nonexcitotoxic convulsant agent. Finally, to address the functional role of this cytokine, we measured the effect of human recombinant (hr)IL-1beta on seizure activity as one marker of the response to kainate. Three and 24 hr after unilateral intrahippocampal application of 0.19 nmol of kainate, IL-1beta immunoreactivity was enhanced in glia in the injected and the contralateral hippocampi. At 24 hr, IL-1beta concentration increased by 16-fold (p < 0.01) in the injected hippocampus. Reactive microglia was enhanced with a pattern similar to IL-1beta immunoreactivity. Intrahippocampal application of 0.77 nmol of bicuculline methiodide, which induces EEG seizures but not cell loss, enhanced IL-1beta immunoreactivity and microglia, although to a less extent and for a shorter time compared with kainate. One nanogram of (hr)IL-1beta intrahippocampally injected 10 min before kainate enhanced by 226% the time spent in seizures (p < 0.01). This effect was blocked by coinjection of 1 microgram (hr)IL-1beta receptor antagonist or 0.1 ng of 3-((+)-2-carboxypiperazin-4-yl)-propyl-1-phosphonate, selective antagonists of IL-1beta and NMDA receptors, respectively. Thus, convulsant and/or excitotoxic stimuli increase the production of IL-1beta in microglia-like cells in the hippocampus. In addition, exogenous application of IL-1beta prolongs kainate-induced hippocampal EEG seizures by enhancing glutamatergic neurotransmission.

Animals↗
PubMed1998

Short-term anabolic effects of recombinant human growth hormone in young patients with a renal transplant.

Renal-transplanted children may present stunted growth, negative nitrogen balance (Nb), and alterations in body composition. Recombinant human growth hormone (rhGH) is a potent anabolic agent which improves nutritional status and Nb. In renal-transplanted children, rhGH increases growth velocity but its effect on nutritional status has not been reported. We evaluated the effect of 6 months of rhGH treatment on Nb, urea nitrogen appearance (UNA), anthropometric indexes, and growth velocity in 14 pediatric patients with a renal transplant. Nb improved significantly (P = 0.02) and was accompanied by a decrease of UNA. A significant improvement was observed also in mid-arm muscle circumference (P = 0.002), arm muscle are (P = 0.001), and arm fat are (P = 0.017). Growth velocity increased in prepubertal patients (P = 0.003). Creatinine clearance and the number of rejection episodes were not affected by rhGH treatment. In conclusion, short-term administration of rhGH improves Nb and UNA as well as the main indexes of body composition.

Adolescent↗
PubMed1993

Detection of rifampicin-resistance mutations in Mycobacterium tuberculosis.

Control of tuberculosis is threatened by widespread emergence of drug resistance in Mycobacterium tuberculosis. Understanding the molecular basis of resistance might lead to development of novel rapid methods for diagnosing drug resistance. We set out to determine the molecular basis of resistance to rifampicin, a major component of multidrug regimens used for treating tuberculosis. Resistance to rifampicin involves alterations of RNA polymerase. The gene that encodes the RNA polymerase subunit beta (rpoB) was cloned. Sequence information from this gene was used to design primers for direct amplification and sequencing of a 411 bp rpoB fragment from 122 isolates of M tuberculosis. Mutations involving 8 conserved aminoacids were identified in 64 of 66 rifampicin-resistant isolates of diverse geographical origin, but in none of 56 sensitive isolates. All mutations were clustered within a region of 23 aminoacids. Thus, substitution of a limited number of highly conserved aminoacids encoded by the rpoB gene appears to be the molecular mechanism responsible for "single step" high-level resistance to rifampicin in M tuberculosis. This information was used to develop a strategy (polymerase chain reaction-single-strand conformation polymorphism) that allowed efficient detection of all known rifampicin-resistant mutants. These findings provide the basis for rapid detection of rifampicin resistance, a marker of multidrug-resistant tuberculosis.

Base Sequence↗
PubMed1993

Epstein-Barr virus infection in HIV-positive patients.

The relationship between Epstein-Barr virus (EBV) viral load in peripheral blood and HIV infection was determined in 103 HIV-infected patients. Epstein-Barr virus was detected by polymerase chain reaction in 75% of the patients, 21% of whom had the more uncommon EBV subtype 2. The highest levels of EBV were found in patients with 100-400 CD4+ cells/mm3 and not in those with more profound immunosuppression. An association was identified between EBV load and HIV proviral levels (p < 0.001), an IgM response to EBV early antigens (p < or = 0.01) and p24 antigenemia (p < 0.01 in patients with > 100 CD4+ cells), but not with other clinical or laboratory parameters. Combinations of different EBV and HIV parameters identified a subgroup of patients with a 2.2- to 4.8-fold risk of > or = 35% decline in CD4+ counts over six months. The association between EBV and HIV markers may reflect a significant pathogenic interaction between the two viruses.

Adult↗
PubMed1993

Direct, automated detection of rifampin-resistant Mycobacterium tuberculosis by polymerase chain reaction and single-strand conformation polymorphism analysis.

A rapid screening test was recently established for the detection of mutations in the rpoB gene of Mycobacterium tuberculosis, a region identified as the locus for rifampin resistance (Rifr). The detection method involved the amplification by polymerase chain reaction (PCR) of the Rifr region and the identification of mutations by single-strand DNA conformation polymorphism analysis (SSCP) of the amplification products. Experience using two different PCR-SSCP formats for the evaluation of BACTEC cultures and sputum is presented here; the previously described manual procedure for the detection for the detection of radiolabelled amplification products and an automated SSCP by which fluorescein-labelled products were detected on a Pharmacia DNA sequencer apparatus. All 17 different Rifr mutations known to date were consistently detected. PCR-SSCP could be used for the evaluation of minimally grown cultures (BACTEC 12B medium with a growth index of < or = 100) and for direct screening of microscopically positive sputa with greater than 10 organisms per field (magnification, x250). Implementation of this technique could result in rapid detection of rifampin resistance in M. tuberculosis, a marker of multidrug-resistant tuberculosis.

Base Sequence↗
PubMed1993

Rapid identification of mycobacteria to the species level by polymerase chain reaction and restriction enzyme analysis.

A method for the rapid identification of mycobacteria to the species level was developed on the basis of evaluation by the polymerase chain reaction (PCR) of the gene encoding for the 65-kDa protein. The method involves restriction enzyme analysis of PCR products obtained with primers common to all mycobacteria. Using two restriction enzymes, BstEII and HaeIII, medically relevant and other frequent laboratory isolates were differentiated to the species or subspecies level by PCR-restriction enzyme pattern analysis. PCR-restriction enzyme pattern analysis was performed on isolates (n = 330) from solid and fluid culture media, including BACTEC, or from frozen and lyophilized stocks. The procedure does not involve hybridization steps or the use of radioactivity and can be completed within 1 working day.

Bacterial Proteins↗
PubMed1992

[The EBNA2 coding region in the viral genome of Epstein-Barr virus (EBV)-positive cases of Hodgkin's disease].

Epstein-Barr virus (EBV)-genome containing cases of Hodgkin's disease (HD) are known to express latent membrane protein (LMP) of EBV but no EBV nuclear antigen 2 (EBNA2). We investigated 35 cases of HD for the presence of EBV genome sequences to know whether EBNA2 coding region is deleted in HD. 27 cases had general EBV sequences, none had evidence of a deletion of EBNA2. 26 cases turned out to harbour EBV type 1, one case had EBV type 2. The absence of EBNA2 protein expression in HD can not be explained by a deletion of EBNA2 coding region. EBV type 1 is the prevalent subtype of EBV in our series of HD.

Acquired Immunodeficiency Syndrome↗