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Biomedical subjects

M Nardi

Publications and source records attributed to M Nardi.

At least 145 records · Page 8Linked to original sources
PubMed1990

Micromethod for demonstrating increased platelet surface immunoglobulin G: findings in acute, chronic, and human immunodeficiency virus-1-related immunologic thrombocytopenias.

A method has been developed for the demonstration of increased platelet surface IgG that uses 1 ml of blood regardless of the platelet count. Platelets are gel filtered to remove plasma and contaminating lymphocytes. They are then reacted with fluorescein-conjugated antihuman IgG and analysed by flow cytometry. Percent positive staining cells vary from 10% to 80% of total cells examined. A platelet antibody index is derived from the product of percent positive staining cells X mean fluorescence intensity of positive staining cells. All patients studied with chronic idiopathic thrombocytopenia purpura (ITP) or human immunodeficiency virus-1 (HIV-1)-related thrombocytopenia had increased platelet surface IgG. Twelve acute children and 11 chronic children had indices averaging 3.5- and 8.9-fold greater than 12 normal children, respectively. Five of 12 children with acute ITP had normal platelet IgG. There was no linear correlation between the platelet antibody index and platelet count. Platelets of patients with acute, chronic, or HIV-1-related ITP displayed autofluorescence. In chronic ITP, the percentage of platelets displaying autofluorescence had a significant negative correlation with the platelet count. This technique will be a valuable diagnostic tool in the pediatric population.

Acute Disease↗
PubMed1990

Effects of capsaicin, tachykinins, calcitonin gene-related peptide and bradykinin in the pig iris sphincter muscle.

Capsaicin-sensitive sensory neurons of the rabbit iris, by releasing tachykinins, exert a major role in the control of pupil motility in response to various noxious stimuli. However, the contribution of sensory innervation to the regulation of iris smooth muscle tone in other mammals species is not known. We have studied the effects produced by electrical field stimulation, capsaicin, substance P, neurokinin A, calcitonin gene-related peptide (CGRP), and bradykinin in the isolated iris sphincter muscle of the pig. Capsaicin (10 microM): a) contracted the isolated sphincter muscle and; b) released immunoreactivity for substance P (SP-LI) and CGRP (CGRP-LI) from this preparation. These two effects were no longer observed at the second exposure to the drug. Electrical field stimulation (10 Hz, 60 V, 0.5 ms for 5 s) produced a biphasic contractile response. The rapid component was inhibited by atropine (1 microM), while the delayed response was blocked by previous exposure to capsaicin (10 microM). Substance P and neurokinin A consistently produced contraction of the pig iris sphincter muscle, substance P being more potent than neurokinin A. CGRP induced a contractile response in more than 50% of the preparations. The tachykinin antagonist [D-Arg1, D-Trp7,9, Leu11]-substance P (3 microM) blocked: a) the effect of substance P (1 nM); b) the delayed response to electrical field stimulation and; c) reduced by more than 50% response to capsaicin. Bradykinin (10 microM) failed to release either SP-LI or CGRP-LI. The contractile response evoked by bradykinin was unaffected by in vitro pretreatment with capsaicin (10 microM).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Dose and schedule effects of cisplatin on the related acute iron changes.

To investigate the relationships between cisplatin and the related erythropoiesis impairment, 14 patients receiving very-high-dose cisplatin (40 mg/m2/day for 5 days) and 17 patients receiving standard-high-dose cisplatin (either a single dose of 100 or 20 mg/m2/day for 5 days) entered this study. Iron, ferritin, hemoglobin, and reticulocyte levels were evaluated before, 4 and 6 days after each course of cisplatin. A complete blood count was obtained weekly. During the 1st week after chemotherapy, iron and ferritin levels significantly increased, and the reticulocyte count decreased. Iron changes depend on the cisplatin dose, but are not related to the different schedules employed. The severity of subacute anemia was found to be dependent on the cisplatin dose administered and on hemoglobin pretreatment levels. Some relationships between cisplatin, iron changes, and the subacute hemoglobin decrease are described.

Adult↗
PubMed1990

Intraperitoneal recombinant alpha-2-interferon alternating with cisplatin as salvage therapy for minimal residual-disease ovarian cancer: a phase II study.

A phase II study was initiated in March 1987 at the Regina Elena National Cancer Institute of Rome to evaluate the efficacy of alternating intraperitoneal (IP) recombinant alpha-2-interferon (r-alpha 2-IFN) and cisplatin (DDP) as salvage therapy for less than or equal to 5 mm residual-disease (RD) ovarian carcinoma. Fourteen assessable patients entered the study. All had received prior chemotherapy (11 with DDP-based regimens); five patients had macroscopic RD (less than or equal to 5 mm), and nine had microscopic RD (histologically positive random biopsies and/or positive cytology and immunocytochemical tests). The response to IP immunochemotherapy was evaluated by laparotomy. Pathologic complete remissions (PCRs) were achieved in seven patients (50%) who have remained free of disease with a median follow-up of 22+ months (range, 11+ to 30+ months). Six patients achieved a stable disease and one presented disease progression. With the exception of chemical peritonitis-induced adhesions, no limiting toxicity was observed. The results obtained in this small, highly selected series demonstrate that a high PCR rate may be obtained with IP immunochemotherapy with DDP and r-alpha 2-IFN as salvage therapy in residual ovarian carcinoma less than or equal to 5 mm after first-line chemotherapy also including intravenous (IV) DDP. Larger comparative studies must be conducted to establish the potential role of IP DDP and r-alpha 2-IFN as compared with either of the single treatments.

Adult↗
PubMed1989

Effective control of CMF-related emesis with high-dose dexamethasone: results of a double-blind crossover trial with metoclopramide and placebo.

To establish the antiemetic activity of both dexamethasone (DXM) and metoclopramide (MCP) in patients receiving i.v. cyclophosphamide, methotrexate, and 5-fluorouracil (CMF), 25 women with stage II breast cancer were entered into this study. A randomized, double-blind, crossover design was employed to evaluate DXM (24 mg in 5 doses) versus MCP (1 mg/kg as a single dose) versus a combination of both drugs (as above) or placebo (PLC). The patients were requested to complete a questionnaire evaluating the antiemetic effect. All but one patient completed the planned antiemetic program during the first four CMF courses. As compared to PLC, both the DXM-MCP combination and DXM alone provided a higher complete antiemetic protection rate (p = 0.01 and p = 0.006, respectively). The DXM regimens were more effective than both PLC (p = 0.004 and p = 0.01) and MCP (p = 0.002 and p = 0.006) in reducing the prevalence of severe vomiting. As compared to MCP, the DXM regimens provided a better control of the nausea (p less than 0.04 and p less than 0.01) and reduced both the episodes and the duration of vomiting (p less than 0.02 and p less than 0.05). The DXM regimens were also associated with a better patient opinion than the PLC (p less than 0.002 and p less than 0.0002). No significant differences were found between MCP and PLC, nor between the DXM regimens. Except for two dystonic reactions, MCP-related toxicity was mild, whereas that induced by DXM was negligible in patients with no contraindications to corticosteroids. As employed in this study, DXM provided safe and effective antiemetic protection for patients receiving adjuvant i.v. CMF. Data available do not support the use of a short-course MCP, either alone or in combination with DXM. The search for better antiemetic treatments is mandatory, especially for patients receiving adjuvant chemotherapy. To date, we recommend the use of DXM as a standard regimen and as a control for further studies.

Adult↗
PubMed1989

Protein S in the first year of life.

Total protein S, free protein S and C4b binding protein were measured in healthy term infants in order to establish the normal levels of these proteins during the first year of life. Total protein S rose from 36.5% of the adult mean level on day 1 of life to 90% between 6 and 12 months of age. Free protein S was 54.2% of the adult mean on day 1 of life, all values were in the adult range by 2 months and the mean value was no different from the adult at 4 months. This relatively high level of free and presumably active protein S reflects low levels of C4bBP at birth (28.8% of the adult mean) and a slow postnatal rise.

Adult↗
PubMed1988

Very high-dose cisplatin-induced ototoxicity: a preliminary report on early and long-term effects.

Acute and subacute audiometric hearing changes were evaluated in 12 patients receiving 35 courses of very high-dose (vhd) cisplatin (200 mg/m2 per course) in hypertonic saline at 4 or 8-week intervals. Audiogical evaluations were performed both before and immediately after each course of chemotherapy, and again after the discontinuation of treatment. A significant drop of the mean hearing threshold (P less than 0.01) at high frequencies was observed even within 48 h from the end of the first course of therapy, with 50% of the patients presenting a hearing loss of more than 15 dB. At the same total dose (200 mg/m2), one course of this regimen provided an incidence of hearing loss of more than 15 dB, which was four times greater than that reported with two courses of standard-dose regimens. The incidence and severity of the hearing impairment progressed further with subsequent courses of chemotherapy. Compared with baseline levels, most patients (75%) receiving at least two courses had a moderate to severe hearing loss, especially involving 4 and 8 kHz. At the end of treatment, 33% of the patients complained of a nondisabling functional hearing impairment. No recovery occurred after chemotherapy had been discontinued for 9-28 weeks. At this dose level cisplatin is markedly ototoxic. The use of hypertonic saline and vigorous hydration are effective means of minimizing the risk of nephrotoxicity, but seem to have no effect on cisplatin-related ototoxicity.

Adult↗
PubMed1988

Intraocular pressure changes in secondary positions of gaze in normal subjects and in restrictive ocular motility disorders.

One hundred normal Caucasian eyes and 29 eyes with restrictive disorders of ocular motility were studied in order to delineate intraocular pressure changes in secondary positions of gaze. Applanation tonometry was performed in the primary position and at an angle of 22 degrees. In patients with restrictive syndromes the changes of intraocular pressure in the secondary positions of gaze were significantly higher (p less than 0.0001) than in normal subjects. The range of variation in normal subjects was 0, +3 mmHg for supraduction and -3, +1 mmHg for abduction. Patients with restrictive syndromes showed changes between +1 and +15 mmHg for supraduction and between +3 and +10 mmHg for abduction. Results obtained in the two groups showed the existence of false negatives. This test is thus a practical and useful diagnostic tool, but its results must be evaluated cautiously.

Adolescent↗
PubMed1988

Anti-human immunodeficiency virus type 1 antibody complexes on platelets of seropositive thrombocytopenic homosexuals and narcotic addicts.

Patients with human immunodeficiency virus type 1 (HIV-1) infection develop an immunologic thrombocytopenic purpura associated with markedly elevated platelet IgG, IgM, and C3C4 as well as serum immune complexes determined by the polyethylene glycol (PEG) method. Analysis of their serum PEG-precipitable immune complexes as well as platelet acid eluates revealed the presence of anti-HIV-1 antibody existing as a complex that eluted in the void volume of a Sephadex G-200 gel-filtration column. The complex binds to washed normal platelets, whereas affinity-purified anti-HIV-1 (gp120) antibody does not. HIV-1 antigen or proviral DNA was not detectable in the immune complexes or platelet extracts. However, anti-antibodies directed against anti-HIV-1 antibody were detectable in the immune complexes as well as platelet eluates. Approximately 50% of eluted platelet IgG contained anti-HIV-1 antibody. Thus the markedly elevated platelet immunoglobulin is partly due to the presence of anti-HIV-1 antibody complexes. This may be responsible for the enhanced platelet clearance and thrombocytopenia in patients with acquired immunodeficiency syndrome-related immunologic thrombocytopenia.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Changes in serum iron levels following very high-dose cisplatin.

A four-fold (P less than 0.001) mean increase in iron levels was found in 18 patients (a total of 36 courses of therapy) with ovarian cancer at the end of a 5-day course of cisplatin (40 mg/m2 per day every 4-5 weeks). The kinetics of these modifications began very early (24-48 h after initiation of therapy): they reached their maximum on the 4th-5th day, coinciding with the last drug administration, and basal levels were recovered after the 10th day. A subsequent eight-fold average increase (P less than 0.001) in ferritin serum levels, beginning 2 days after the iron changes, was observed, but showed a slower regression (after the 15th day). Reticulocyte counts were lowered (P less than 0.001) with the same time-course of the iron increases, but returned to pretreatment levels within 2 weeks. Total bilirubin and serum glutamate-pyruvate transaminase showed significantly delayed increases compared with iron. The results are in keeping with a reduced iron utilization by the erythroid precursors, but other mechanisms cannot be excluded. There is no statistical correlation between the early iron increases and the subsequent hemoglobin nadir values.

Cisplatin↗
PubMed1987

A randomized trial comparing alizapride alone or with dexamethasone vs a metoclopramide-dexamethasone combination for emesis induced by moderate-dose cisplatin.

To evaluate the antiemetic effectiveness and toxicity of a novel congener of metoclopramide (MCP), alizapride (AZP), 29 patients receiving cisplatin (50 mg/m2) alone or with adriamycin (40 mg/m2) were entered into a randomized cross-over trial comparing moderate-dose AZP (2 mg/kg for 4 doses) administered alone or with dexamethasone (DXM) (8 mg for five doses) vs a standard combination of MCP (1 mg/kg for four doses) and DXM (as above). With the dosage and schedule used, AZP provided only limited antiemetic protection, with less than 10% of the patients free of emesis. The AZP-DXM combination was significantly more effective than AZP alone in reducing the intensity of the emesis (P less than 0.03). The incidence, however, was statistically unaffected. The additional toxicity of DXM was negligible. Except for the patients' preference for MCP-DXM (P less than 0.01), no differences could be found between the DXM-based regimens, although a trend towards a better antiemetic effect with the MCP combination was evident. The benzamide-related dystonic reactions were equally distributed. Among the 11 patients affected there were 6 who required specific treatments. Unfavourable prognostic factors in the patient population could provide a reasonable explanation for the disappointing antiemetic protection obtained with all the regimens evaluated in this study.

Adult↗
PubMed1987

Na-Stimulated Transport of l-Methionine in Brevibacterium linens CNRZ 918.

The transport of l-methionine by the gram-positive species Brevibacterium linens CNRZ 918 is described. The one transport system (K(m) = 55 muM) found is constitutive for l-methionine, stereospecific, and pH and temperature dependent. Entry of l-methionine into cells is controlled by the internal methionine pool. Competition studies indicate that l-methionine and alpha-aminobutyric acid share a common carrier for their transport. Neither methionine derivatives substituted on the amino or carboxyl groups nor d-methionine was an inhibitor, whereas powerful inhibition was shown by l-cysteine, s-methyl-l-cysteine, dl-selenomethionine and dl-homocysteine. Sodium plays important and varied roles in l-methionine transport by B. linens CNRZ 918: (i) it stimulates transport without affecting the K(m), (ii) it increases the specific activity (on a biomass basis) of the l-methionine transport system when present with methionine in the medium, suggesting a coinduction mechanism. l-Methionine transport requires an exogenous energy source, which may be succinic, lactic, acetic, or pyruvic acid but not glucose or sucrose. The fact that l-methionine transport was stimulated by potassium arsenate and to a lesser extent by potassium fluoride suggests that high-energy phosphorylated intermediates are not involved in the process. Monensin eliminates stimulation by sodium. Gramicidin and carbonyl cyanide-m-chlorophenylhydrazone act in the presence or absence of Na. N-Ethylmaleimide, p-chloromercurobenzoate, valinomycin, sodium azide, and potassium cyanide have no or only a partial inhibitory effect. These results tend to indicate that the proton motive force reinforced by the Na gradient is involved in the mechanism of energy coupling of l-methionine transport by B. linens CNRZ 918. Thus, this transport is partially similar to the well-described systems in gram-negative bacteria, except for the role of sodium, which is very effective in B. linens, a species adapted to the high sodium levels of its niche.

Journal Article↗