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Biomedical subjects

E Marchi

Publications and source records attributed to E Marchi.

At least 55 records · Page 3Linked to original sources
PubMed1990

Lymphocyte subsets in bronchoalveolar lavage fluid and in circulating blood in epidermoid bronchogenic carcinoma.

Alveolar macrophages, lymphocyte and granulocyte percentages, together with OKT3+, OKT4+, OKT8+ lymphocyte subsets and OKT4+/OKT8+ ratio, were evaluated in bronchoalveolar lavage (BAL) fluid and in peripheral venous blood (PVB) of neoplastic and nonneoplastic subjects, in order to assess these aspects of immunity in neoplastic disease and to find out if the modifications in the bronchoalveolar environment are correlated to the ones in the circulation blood. BAL was performed in 30 patients undergoing fiberoptic bronchoscopy to ascertain the presence of lung cancer. Twelve of them had positive findings for epidermoid bronchogenic carcinoma, while in the remaining subjects the diagnosis was not confirmed. The 30 examined subjects were then grouped according to their smoking habit. In PVB, no significant difference was seen between neoplastic and nonneoplastic subjects, whereas in BAL the neoplastic patients showed a significant increase of lymphocytes OKT3+ and OKT8+. This tends to confirm that PVB is not a good indicator of organ immunity and may justify the reduced activity of alveolar macrophages in subjects affected by bronchogenic neoplasia. Between smokers and nonsmokers, lymphocyte subsets showed more significant differences than between neoplastic and nonneoplastic subjects (decrease of T4+ lymphocytes, increase of T8+ lymphocytes and, therefore, reduction of T4/T8 ratio); there were also scalar variations in the three groups (smokers with cancer, smokers without cancer and nonsmokers without cancer). Thus, the possible autonomous role of cigarette smoke and the presence of neoplasia in the immunity alterations of the alveolar environment with final joint effects were confirmed. These data may indicate a possible correlation between cigarette smoking, immunological alterations in BAL and the onset of bronchogenic carcinoma.

Adult↗
PubMed1990

Evidence for a reduced heparin cofactor II biological activity in diabetes.

A reduction of heparin cofactor II (HCII) biological activity, despite its normal plasma concentration, is reported in insulin-dependent diabetic patients. A good linear correlation between HCII activity and concentration is present in normal controls but not in diabetics. In these subjects HCII activity correlates inversely with fasting blood glucose and glycated proteins but not with Hb A1. These data demonstrate the presence of a depressed HCII activity in the presence of its normal plasma concentration in insulin-dependent diabetics and suggest a role for short-term metabolic control in conditioning this phenomenon.

Adult↗
PubMed1990

Comparative efficacy and tolerability of clarithromycin and amoxycillin in the treatment of out-patients with acute maxillary sinusitis.

The efficacy and tolerability of clarithromycin and amoxycillin in the treatment of acute maxillary sinusitis were compared in an open, Phase III multi-centre study. Sixty-one out-patients (40 males, 21 females) received clarithromycin (two 250 mg tablets twice daily) and 59 (34 males, 25 females) out-patients received amoxycillin (two 500 mg capsules twice daily). Fifty-seven and 47 patients in the clarithromycin group were evaluable for clinical efficacy and bacteriological effectiveness, respectively. In the amoxycillin group, 57 and 40 patients were evaluated for clinical efficacy and bacteriological effectiveness, respectively. Body temperature, bacteriological culture results, blood and urine chemistries, and clinical signs and symptoms were evaluated prior to drug administration, between Days 4 to 6 and between Days 9 to 11 of treatment, and within 48 hours and, if required, 6 weeks after the end of treatment. Clinical signs and symptoms improved significantly (p less than 0.001) in both treatment groups. When evaluated within 48 hours after the end of treatment, there was no significant difference between the clinical success rate for clarithromycin (91%) and amoxycillin (84%) nor in the number of patients whose original pathogen was eradicated (89% clarithromycin, 93% amoxycillin). Six patients reported adverse events, 2 with clarithromycin (urticaria, gastro-intestinal) and 4 with amoxycillin (2 urticaria, 2 gastro-intestinal). Clarithromycin was comparable to amoxycillin with respect to clinical efficacy and tolerability and offers a useful addition to the available therapies for the treatment of acute maxillary sinusitis.

Administration, Oral↗
PubMed1990

Possible role for increased C4b-binding-protein level in acquired protein S deficiency in type I diabetes.

In this study, total protein S (PS) immunological levels, free-PS and C4b-binding-protein (C4bBP) concentrations, and PS functional activity were investigated in insulin-dependent (type I) diabetic patients and compared with nondiabetic subjects. Mean total PS antigen concentration was not different between diabetic patients and nondiabetic subjects, whereas free-PS levels and PS functional activity were significantly reduced in diabetic patients. C4bBP was increased in diabetic patients and correlated with HbA1 levels. This study shows that type I diabetic patients have depressed free PS and PS activity despite the presence of normal total PS concentration and suggests that this phenomenon is probably linked to the increase of circulating C4bBP.

Adult↗
PubMed1989

Hyperglycemia may determine fibrinopeptide A plasma level increase in humans.

The effects of hyperglycemia on plasma fibrinopeptide A (FPA) levels in normal subjects are reported. An increase of FPA concentration parallel to sustained hyperglycemia was observed; when the glycemia returned to basal values, FPA showed values in normal range. Heparin infusion was able to significantly decrease the hyperglycemia-induced augment of FPA levels. Isovolumic-isotonic NaCl solution infusion produced a slight (NS) increase in FPA levels; however, mild hyperglycemia, achieved by glucagon, was also able to produce a significant increase in FPA concentration. These data demonstrate the direct role of hyperglycemia in conditioning FPA level, and suggest that hyperglycemia, by itself, is a sufficient stimulus to produce thrombin activation in humans.

Adult↗
PubMed1989

Hyperglycemia-conditioned increase in alpha-2-macroglobulin in healthy normal subjects: a phenomenon correlated with deficient antithrombin III activity.

Induced hyperglycemia in normal subjects increases alpha 2-macroglobulin (alpha 2M) activity and alpha 2M concentration and reduces antithrombin III (ATIII) activity, while it does not affect ATIII plasma concentration. Hyperglycemia-determined variations in ATIII activity and alpha 2M molecules are correlated in an inverse and parallel fashion. A compensatory role for the increase in alpha 2M in the regulation of the coagulation system may be hypothesized. Moreover, these data provide evidence that hyperglycemia may decrease, directly, the biological function of some proteins and may influence the levels of some risk factors for the development of complications in diabetes.

Adult↗
PubMed1989

Structure-activity relationships in 4-deoxypyrido[1',2'-1,2]imidazo[5,4-c]rifamycin SV derivatives.

New 4-deoxyhalogenopyrido[1',2'-1,2]imidazo[5,4-c]rifamycin SV derivatives (V-VIII) have been prepared as an extention of a program which led to the synthesis of analogous pyrido- and alkylpyrido compounds (I-IV) displaying a low level of g.i. absorption. The new compounds give comparatively much lower ED50 p.o./s.c. ratios showing a recovery in the extent of oral absorption. XPS, N.M.R., and HPLC data rationalize this activity in hydrophilicity due to the electron-withdrawing inductive effect of the halogen atoms bound to the pyridoimidazo system. This effect is exerted in particular on the negatively charged N(2'), and is the opposite as that exerted by the alkyl groups present in (I-III).

Bacteria↗
PubMed1989

Synthesis of 2-hydroxyacetyl-7-acetyl-xanthone, a new xanthone derivative endowed with antianaphylactic, analgesic, and antiinflammatory activities.

2-Hydroxyacetyl-7-acetylxanthone (V), a new xanthone derivative, was synthesized in four steps starting from xanthene, by two synthetic approaches. The new compound displayed antianaphylactic activity in the PCA test and in the anaphylaxis shock test in rats. It also displayed analgesic activity in the writhing test in mice, and antiinflammatory activity in the carrageenin edema test in rats. The activity of the new compound has been tentatively interpreted on the basis of its chemical and structural analogy with known drugs.

Anaphylaxis↗
PubMed1987

Sensitivity to rifaximin and rifampicin of Mycobacterium tuberculosis isolated from guinea pigs treated orally with rifaximin.

The in vitro sensitivity of the H 37 RV strain of Mycobacterium tuberculosis to rifaximin and rifampicin was determined by evaluating both the antimycobacterial activity of the two rifamycin derivatives after oral administration to infected guinea pigs and the influence of rifaximin on the susceptibility to rifampicin of the isolated strain from spleen, lungs and liver. The results showed that after oral treatment with rifaximin no changes regarding the sensitivity of the strain to rifaximin and rifampicin were seen.

Animals↗
PubMed1987

Comparison between sulbenicillin and piperacillin levels in serum and in bronchial secretions--a pharmacokinetic study.

In order to assess pharmacokinetic differences between sulbenicillin (S) and piperacillin (P), two penicillin derivatives, 24 in-patients, 12 males and 12 females mean age 59.4 years, suffering from recurrent bronchial infections were enrolled. Patients were randomly allocated to S (12 patients) and to P (12 patients) and were given 2 g i.m. every 12 h of the awarded antibiotic, for a 7-day period. At the first and 7th day blood samples (0.25, 0.5, 1, 2, 4, 6, 8 and 12 h after dosing) as well as sputum samples (1, 2, 4, 8, 12 h after dosing) and urine samples (3, 6, 9 and 12 h after dosing) were collected, and the levels of S or P were determined by bacillus subtilis test. The pharmacokinetic analysis was performed by a standard program. On day 1 and 7 the mean peak serum concentration occurred at the first hour for S (39.9 +/- 5.2; 40.9 +/- 5.1 mcg/ml, respectively) and for P (32.2 +/- 5.4; 33.1 +/- 5.4 mcg/ml, respectively). Serum AUC0-12 and AUC0-00 (mg/l.h) levels of S were significantly higher (p less than 0.01 or less) than those of P on day 1 and 7. Similarly MRT (8 h) and Cmax (mg/l) where higher but only on day 7. Sputum AUC0-12 (mg/l.h) level of S was significantly higher (p less than 0.05) than that of P on day 1 and 7. In conclusion serum and sputum S appear to have a different pharmacokinetic profile in respect to P. However, when compared to the AUC, both drugs reach antibacterial levels.

Aged↗
PubMed1987

Some aspects of "deep lung" cellular immunity in chronic bronchitis before and after therapy with tiopronin.

Fifteen patients suffering from obstructive chronic bronchopneumonia in a clinical steady-state phase received 0.6 g of tiopronin once a day during 10 days per os. The lymphocyte subsets (OKT3, OKT4 and OKT8) have been identified in peripheral blood and in bronchoalveolar lavage liquid (BAL) before and after treatment and phagocytosis has been evaluated in pulmonary alveolar macrophages (PAM) (phagocytosis index, phagocytosis percentage, superoxide-ion production). A highly significant improvement in the phagocytosis process has been observed in the PAM, as well as an increase in the number of lymphocytes T3 and in the T4/T8 ratio (due to an increase in T4 lymphocytes) in the BAL; while in peripheral blood T3 and T4 lymphocytes and the T4/T8 ratio only showed a nonsignificant increase after treatment. The possible mechanisms on which these variations are based have been investigated.

Aged↗
PubMed1986

In vitro and in vivo evaluation of L/105, a new topical intestinal rifamycin.

L/105 (4-deoxy-4'-methylpyrido [1',2'-1,2] imidazo [5,4-c] rifamycin SV; INN: Rifaximin) is a new rifamycin active in vitro against both gram-positive and gram-negative microorganisms. The activity of L/105 was comparable to that of rifampicin and, against gram-positive bacteria, higher than that of neomycin. The antibacterial activities of L/105 and rifampicin were equally affected by the highest size of inoculum used (10 cells/ml) and they were equally bactericidal against Staphylococcus aureus and Escherichia coli. The speed and the degree of development of resistance to L/105 were quite superimposable on those of neomycin. In vivo, L/105 did not show therapeutic activity by oral route in the staphylococcal infection in the mouse till the highest dosage used (10 mg/kg b.w.); under the same conditions, gentamicin was equally ineffective. After subcutaneous administration, L/105 showed therapeutic activity (ED50 = 0.46 mg/kg b.w.) practically superimposable on that of orally administered rifampicin.

Administration, Oral↗
PubMed1985

4-Deoxypyrido[1',2':1,2]imidazo[5,4-c]rifamycin SV derivatives. A new series of semisynthetic rifamycins with high antibacterial activity and low gastroenteric absorption.

A series of 4-deoxypyrido[1',2':1,2]imidazo[5,4-c]rifamycin SV derivatives (6-11) were prepared that demonstrated high antibacterial activity suitable for an intestinal disinfectant. These compounds are zwitterionic in nature and are poorly absorbed through the gastroenteric tract but maintain the ability to cross the bacterial cell wall. X-ray crystallographic data are presented to demonstrate the zwitterionic nature of these compounds. The structure-activity relationship of this novel series of antibiotics is discussed and the derivative with the highest ratio between subcutaneous and oral activity (6) was selected for clinical development. At the outset of this work several 3-(quaternary ammonium bromides) (1-5) were prepared and tested for antibacterial activity. These compounds were demonstrated to be too polar to even cross the bacterial cell wall but led to the synthesis of 6-11.

Animals↗
PubMed1985

A study of structure-activity relationships in 4-deoxypyrido[1',2'-1,2]imidazo[5,4-c]rifamycin SV derivatives by electron spectroscopy for chemical analysis and 1H NMR.

A new class of rifamycins, 4-deoxypyrido[1',2'-1,2]imidazo[5,4-c]rifamycin SV derivatives, has been synthesized. They are potent antibacterial agents and are not absorbed at the gastrointestinal level and can therefore probably be used as antibacterial intestinal disinfectants. From the present X-ray, electron spectroscopy for chemical analysis, and 1H NMR study, it appears that this peculiar pharmacokinetic behavior is mainly to be attributed to the fact that the pyridoimidazo system exists in these compounds in a mesomeric betaine form, bearing one positively and one negatively charged nitrogen. If it is assumed that rifamycins are generally absorbed by passive diffusion, the presence of the two oppositely charged nitrogens, together with the presence of the phenolic hydroxyls, means that these molecules are ionized at all pH values encountered along the gastrointestinal tract, which thus prevents their absorption. These molecules also display a strong tendency to self-associate both in solution and in the solid state, and the increase in molecular size may also play a role in preventing their absorption.

Magnetic Resonance Spectroscopy↗
PubMed1984

The synthesis of 4-deoxypyrido[1',2'-1,2]imidazo[5,4-c]rifamycin SV derivatives.

Two series of new semisynthetic rifamycin SV derivatives have been prepared. One of them bears a quaternary ammonium salt at C3 (1-5), and the other a pyridoimidazo system condensed at C3 and C4 (6-11). While compounds 1-5 had poor antibacterial activity in vitro, compounds 6-11 were found to be highly active in vitro but poorly absorbed in vivo. They could thus have potential as agents in the therapy of intestinal infections. The synthesis and the 1H NMR structure determination of these new compounds are reported.

Magnetic Resonance Spectroscopy↗
PubMed1984

X-ray crystal structure of 4-deoxy-3'-bromopyrido[1',2'-1,2]imidazo[5,4-c]rifamycin S.

This paper reports the determination of the X-ray molecular structure of 4-deoxy-3'-bromopyrido[1',2'-1,2]imidazo[5,4-c]rifamycin S, carried out in order to unequivocally define the general structure of a new series of rifamycin SV derivatives, which are potent antibacterial agents, and are not absorbed at the gastroenteric level. They have been prepared by Alfa Farmaceutici, Bologna, by condensing 2-aminopyridine derivatives to 3-bromorifamycin S. The solid state X-ray study has confirmed the structure proposed on the basis of 1H NMR studies in solution. It has also shown that the newly formed pyridoimidazo system is in a mesomeric betaine form, the pyrido nitrogen being positively charged and the imidazo nitrogen being negatively charged. This feature is believed responsible for the pharmacokinetic behavior of these new drugs, one of which, denoted either as rifamycin L 105 or rifaximin, is actually under clinical trial as a topical intestinal disinfectant.

Magnetic Resonance Spectroscopy↗